I'm going to make a theory that fits acceptable facts; I love Tamarind-Abbey but part of that love lies in how ridiculously sad-sack they are (the Lyrans invading them just before Stone's Coalition liberated Terra, having them withdraw from the Coalition after doing heavy-lifting against the Blakists throughout the Jihad but just before the rewards of victory were being handed out is one of my favorite moments), so I think I'm up to it.
FM3145's ratings and the Shattered Fortress narrative are pretty unambiguous that man-for-man and mech-for-mech the Marians are better than the Tamarinds (and by late 3150 for one the 7th Tamarind Regulars are definitely much worse than they were in 3145). If it was an even fight, the Marians won. If the Tamarinds stuck it out, it meant they took serious losses when they lost instead of cursory losses (the Tamarinds didn't always stick it out). The Marians didn't lose in even fights to the Tamarind Regulars, though. The lost in multi-regiment team ups (the one involving the mauled 7th also involving the much better 1st) and to Camacho's Caballeros until Illyria, which came down to a strategy. (Tamarind-Abbey successfully masking their strategic redeployment, the Illyrian system defenses being countered by Tamarind assault droppers, the initial ground defense able to be overwhelmed by multiple regiments and a swarm of mercs thrown in, then the locals (cultural Rasalhagues, bear in mind) revolted in the Duchy's favor instead of forming a resistance, and then there was finally an actual fight when III Legio returned from the Gibraltar prominence, which was lost.
I assume the Canopan punitive expedition is what has III Legio so exposed for so long making all that possible though; absent knowing that the Magistracy regards the matter as settled Alphard can't be uncovered. So Killgore is running around like a one-armed paper hanger, having to use his own spearhead as a reserve. Anyways it's possible to make a theory that doesn't require anything ridiculous; the biggest thing I think is the Illyrian sympathetic revolt instead of a resistance. That probably decided everything regarding things being as they are; nothing actually contradicts there being an eventual Marian counterstrike other than the notion that they can't expose themselves to possible Canopan action (which is just a notion)- Illyria falling quickly (or at all) required the locals. The Illyrian campaign was risky if discovered but feasible (Killgore was pushing on an open door for one or two worlds he took but didn't realize it). As for Duke Fontaine hiring mercenaries it's the era for it and he's in funds as the House Marik patriarch (he once absconded from his capital with Mule packed full of artwork like a Napoleonic Bourbon fleeing Naples). He's probably good for it.
We go in parts like Jack says
The Illyrian Revolt I see it very doubtful since nowhere says it, it is but the last attempt at organized revolt dates from 3085 I think there is nothing even remotely organized, there are ethnic Rasalagheans but they should not be a majority by far
In terms of strategies, you can be lucky once, but always?
As for the Tamarindo units, especially the 7th Regulars, they twice crashed and were beaten, but one of their battalions was destroyed in Tormentine, but after months they appear full force to attack and with the same rank of veteran?
The 8th Regulars I think they were Regular in the best of cases and I don't see that they could face Legio I or II Legio face to face and stay there for a long time.
The 1st Regulars if he is Elite, the same as the Camacho Caballeros, but they cannot be everywhere, another thing that annoys is that they put the Alba Wing and the II Caelum Wing off of when both units are Veteran / Elite and fanatic loyalty, in the story they say little more than break ranks and run, as it does not fit with everything previously written.
Apart from the little speech on moral superiority and shooting surrendered prisoners ,,,,, where was Marik?
If I have to accept this, I hope that in the almost impossible case that the next author gives us a twist and victory, no one will be shocked if the good duke and his officers Camacho included end up crucified on the shoulder of a total mech, if we leave to behave like savages return of attention should be something that does not scandalize anyone, right?
Another Theme is our Mercs, fundamentally the Dragonslayers to be at 100% in 3145, in the campaign they are at 30% and they look like a band of beggars
