I had same experience in Undead Scourge. Contract to destroy two locations. First was 6 Honor Guards and 15 Legionnaires, I lost 4 men there and went to second, there were 6 ghosts, 5 Fallen Heroes and 19 armored zombies, 30 in total, so my party was almost wiped out, I retreated and abandoned the contract. Yep, it’s a bit unfair but that’s more of balance issue, not gameplay.
The mid to late game and crises balance has a lot of issues indeed. I wonder what the solution would be.
Perhaps the primary thing to consider is making mercs stronger, since clearly they’re not significantly tougher than any single lategame enemy, and the game throws hordes of them at you by the end, as if they were supposed to be manageable without brutal losses. Balancing this is probably no easy task. The early game feels fine overall (talking from a Veteran perspective), but difficulty seems to ramp up too quickly, with most companies ending up underpowered and undergeared to face contemporary opposition after a couple of game months or so.
There’s several factors that need to be tinkered with, most likely. Since the early game feels fine, one variable to tackle is mercenary growth curves, so that early levels work more or less like they do now, but the upper ones represent larger improvements, possibly increasing the number of points and/or stats you can improve per later level up. An alternative is to make experiance gain faster, and raise the level cap so that the average player company reaches the lategame with several more levels under their belt.
Another aspect which needs revision is higher-end recruits. They need to be more reliable, or at the very least the player should be shown more information about the candidates they’re about to shell out serious sums for. Currently, they’re too expensive and too random, as money isn’t exactly easy to come by after a certain point, and you might end up spending your entire savings on a supposed professional who turns out to be not that significantly better than a good farmhand.
Mid to late game contract profitability is perhaps another variable to tweak, but it might not be necessary to do so if mercenaries reach this stage stronger, and able to reliably complete missions without excessive losses.
As for endgame crises, I suppose enemy numbers could be thinned out, but a) that’s not very thematic for a civilization-threatening event, and b) if other factors are revised, it might not be necessary to weaken endgame forces.