In General for the Clans, those who build are at a disadvantage compared to those who simply trial for either production or factories. Technically Clan society should have all the technology needed to turn even a single one of the homeworld systems into a serious economic engine.
At around 1 billion total over the number of worlds while also having the near full Star League tech base they should not really be looking at the Inner Sphere for war.
The problem is that here they are facing an enemy they really know nothing about, one that has been preparing steadily for over 30 years.
An enemy with a much higher population, a much deeper and wider technology base.
The Clans should have started ramping up industrial production, light, heavy, and space industry the moment talk of an invasion started. They need a lot of civilian Industry that could be switched over to dual-use easily enough. Space Industry to have convoys coming back and forth from the Clan Homeworlds.
Culturally they do not have the background to do that. If they did the cast members of the Homeworlds would not be showing such terrible life expectancies.
Uhm, I think they actually MIGHT. consider your population distribution and how war is waged within the Homeworlds, and the 'culture' of the Warrior Caste as opposed to the general culture of the other 99% of their population. It's actually not unusual for Caste based systems to have radically different outcomes to non-caste based systems, as social and societal expectations are going to be
radically different.
For example, the "Youth obsession" within the Clan warrior caste plus the nature of their Trial and the tie in to reproduction, could well create a situation in which an otherwise functional society has a warrior class that is remarkably short-lived on an individual level, with rapid 'generational' shifting and a loss of institutional knowledges such that you end up with a crap battle theory despite having what is technically the best MOS training...because it's not crap for the wars and conflicts you're used to fighting. What defines Clan trials?
Well, the need for heavy-lifting on intelligence work really isn't there. Combat occurs using pre-defined forces, and is limited to pre-announced engagements. This means immediate firepower is far more important than, say, sustained efforts, and that logistics planning ends up being limited to the next engagement, because more is simply unnecessary.
Thus, your training will focus on what? Gunnery, and piloting. Because "Leadership" is defined as "Toughest guy in the room", there is a bias toward good gunners and good pilots with some influence toward personal charisma. Their system is the kind that G.A.Custer would have done exceptionally well in (being highly charismatic, a good horseman, and an excellent shot). it's not the sort of system that would do well with, say, Ulysses S. Grant or Phillip Sheridan.
Not that most of the Inner Sphere is in any better shape, mind you. For a meritocratic system to work, it must possess an internal system of evaluation, The Clan system's internal system can be best described as using Duelling performance as a preliminary evaluation method, while the Inner Sphere (most of it, anyway) relies heavily on feudal connections and both systems rely heavily on bloodlines.
"The best of the pool that is available, that meets the initial standards".
IOW the Clan warrior caste biases toward very good pilots, who are very good shots, other skillsets have to be subordinate to that being very good pilots whom are very good shots.
BUT...
They COULD have a broader strategic vision-it's just less likely given the level of priority being a very good duellist holds over all other considerations. Such a warrior would be
outstandingly dangerous, particularly if they are also highly charismatic (which most Clan Warriors are, for the same reasons they bias toward very good pilots whom are very good shots-the rise in rank and the selection process for reproduction favors charisma highly due to their pseudo-democracy and how sibkos are prioritized).
This side effect is even suggested in the Clan invasion era novels, with POV characters in at least a couple of them noting how
beautiful or Handsome Clanners are relative to the rest of the population.
Imagine facing an army of psychopathic movie stars or pop-idols whom are each individually trained to be extremely lethal fighters with fitness-model physiques, and some of them are big enough to look down on NBA pro basketball players.
but psychologically, the Clans (at least a few of them) may have had some selection toward forward thinking. Clan Wolf, for example, in the Canon, actually considered supply lines and buffered for losses, making their offensive more effective across a wider front that penetrated deeper with less degradation of performance.
It's POSSIBLE for a Clan in this setting to think further ahead...it's just that said Clan would have to be remarkably STRONG to be able to afford to build more, instead of trialing for what someone else has built, and it would require one of those "one percent of the one percent" who think further ahead and can consider adapting to losses as opposed to focusing on their victory.
My projections:
Clan Star Adder and Clan wolf will be dominant in the invasion in this setting, because both have more grasp of the 'lesser skills' of warfare such as gathering intelligence and structuring supply lines. Clan ice Hellion will take severe losses or even become non-viable once they hit competent levels of resistance, the Jade Falcons will be right behind the Wolves in performance (just like canon) because Crichell and Chistu are actually pretty clever. Ghost Bear will perform well, particularly in the occupation phases, and Hell's Horses will ALSO peform well.
The Novacats are screwed, but they're not alone in being screwed, because they and the Steel Vipers both have internal cultures that hamstring effective efficiency. The Goliath Scorpions may have enough historical perspective to handle some intel and strategic work, but they'd have to be 'straight' to do it (getting high regularly doesn't help you with the kind of mental lifting necessary to execute strategic objectives. Necrosia is a mind-altering drug...) The Smoked Jaguars will burn bright for the first few months, and lose their asses because their operational predilections, viciousness, and negative habits, as well as their extreme focus on aggressive piloting and gunnery means they'll win fights and lose battles, win fights and lose strategic objectives, and so on.
The Blood Spirits? might have a chance for a while, but will run up against their insular habits and unfortunate tendency to make enemies, though their friendships might save them (Snow Ravens) at least for a time.
My prediction of the first year after the Clans hit, will be a grimly darwinian selection process in this 'verse. The more aggressive, (bigoted) Clans will experience significantly and singularly lopsided casualty rates. Some of the usual suspects will end up needing to be absorbed by other Clans due to lost viability (Fire Mandrill), or having to rewrite their dogmas and doctrines to survive (bets on Blood Spirit, Steel Viper, though The Spirits have a better chance of doing so successfully)