With the possible exception of technological prowess (Something Terra could absorb in the blink of an eye), the Clans really have nothing competent to offer Terra in terms of governance.
With ilKhan Make-Everyone-My-Enemy Alaric Ward at the helm, I have my doubts about whether we'll see any of the potential benefits of an ilClan, but I would argue that in the abstract at least that an ilClan-led Star League could offer the inner sphere a better way of waging war. Prior to the Clans returning, and prior to the total war of the Jihad, the average citizen was rarely depicted as having a lot of stake in whose flag flew over their world. If they cared, they were probably involved in the military or the state in some way and for everyone else, life ground on regardless. War was mostly a weird pasttime of the nobles in charge, rather than anything prosecuted to the hilt. So, there's a precedent for the conflicts in the inner sphere being a caricature of war. Fundamentally, can we say that this is really all that different from the clan system where this is made plain and disputes are formalized into trials? For anyone participating in the ilClan's Star League, instituting combat trials rather than open warfare would be a marked improvement on the way this is conducted in the inner sphere. a strong clan-based Star League could enforce these standards and take action against habitual violators of it.
Instead of bemoaning Social Generals buying their way into commands and wasting lives for their hubris, rank could be won through Trials of Position, or if someone still manages to buy their way into power one way or another, they could be dealt with through Trials of Refusal and Grievance.
Instead of fighting a battle for control or possession of an important factory right there on the factory grounds and damaging it in the process you could fight a distant Trial of Possession for the facility, and risk no civilian lives, nor the integrity of the prize. Instead of making an objective raid and having to fight your way to the objective, take it, and escape, you could just Trial for possession of it.
Instead of risking another Jihad, another all-out war across known space, war could be compartmentalized. tidy.
More radically, it does not seem impossible that someone might see the virutes in the clan means of producing warriors. You can certainly argue that the clans have never necessarily lived up to the premise, but Iron Wombs and Bloodnames offer the possibility of insulating the lower castes from the horrors of war. If you take the genes of successful warriors and use them to produce more warriors, selecting the best of them lets you staff a force with olympian grade people, trained for far longer than a normal civilian could do, and their lives are disconnected from the worldly attachments that make war such a tragedy. A warrior who did not have to worry about leaving a spouse or freeborn children behind could more easily fight without reservation. Knowing that fighting boldly, valliantly, successfully is going to do more to secure the progression of their bloodline than taking actions to preserve their life would, means that they can fight without hesitation, make sacrifices knowing that they will live on. There is no family waiting at home for a parent or a sibling who will never return.
and from a Meta angle, the notion of Trial Culture becoming widespread is an excellent excuse for small scale battles with large scale meaning behind them. Only want to fight a 4 on 4, but want that fight to be significant? This is a trial for something important, and there's only eight machines on the field because that's what the bidding produced.
And maybe you're onboard with the idea of formalizing battle along those lines, but still object to the austere and authoritarian aspects of Clan Culture? Well, not only are you in luck because Clan Wolf is historically permissive and hands-off with their lower castes (had virtually zero issues with the society in the Reavings because their scientists weren't unhappy enough to get involved, absorbed clan widowmaker in a dispute that began over harsh treatment of lower castes, has been stated to be hands-off numerous times) and they are at the helm, so there is every bit of potential to see a similarly free attitude about people who aren't part of fighting and fighting related industries. Beyond that, the spartan lifestyle of the clans makes sense for the Warrior Caste, and perhaps some of the people in direct interface with them because adveristy and austerity can foster strength, but I would argue that the imposition of that lifestyle upon all citizens of the clan was a necessary measure in the resource poor hellscapes of the clan homeworlds, but is unnecessary and wasteful in the plenty of the inner sphere. If you are starving aboard a life raft while adrift at sea, rationing your food supply makes sense. You would be foolish not to. But applying the same attitude to a cozy holiday feast is madness. Just so, there is no reason that the clans would have to continue that for everyone under their rule in the inner sphere.
Perhaps there isn't much of that which is of immediate and great benefit to Terra in specific, but there are merits to this notion for members of a new star league as a whole.
