Yeah, I remember those being rehashed in the FM: Mercenaries, too. But, they don't go into 'what can you expect at the other end'. It's almost as if they expect you're familiar with all the other sources, and that's difficult to do, especially with a lot of sources out of print.
I was overjoyed at Combat Manual: Mercenaries, because I was expecting at least a small sentence or paragraph explaining each unit's origins. Sadly, there were still a handful that I had no idea how they got started. Lindon's Battalion seems to come to mind, but I'm not positive. They were few, I only recall feeling disappointed 5 times. But, I don't recall which all, because there are so many. (Aside: did the mystery of Wylie's Coyotes ever get solved?)
I don't have the old Merc Handbook. At some point, I suppose I can pick up the PDF, but I don't sit well in front of a computer screen for long hours reading. I prefer to recline when reading something in-depth.
Not only is it dating of the source material and equivalent access, but I seem to see a schizophrenia regarding force composition regarding Mechs and other stuff. They want to encourage players to feel they have control with whatever force they're playing with, but the opposition seems rather lacking. If the hinting at large numbers of forces is to be believed, and you're using the same force in a lot of games, or someone is willing to play opfor for a campaign for said force, then there seem to be a lot of Mechs and tanks and other things readily available.
Mechs being scarce makes for a boring universe, but if done right, that means your MechWarriors really are the King- and Queen-shits of any world they land on. Lots of enemies to shoot at makes something like interplanetary raids require a lot more support and prep for even something as small as a lone warrior to go bounty-hunting.
I know which way I would prefer, but I wish the guys in charge would pick one and run with it. I would gladly bow to that. Or, heck, set up competing BT realities. You can have the world where Mechs are scarce, and planets seeing a large war resort to massive local builds of vehicles and militiaMechs, which are always outperformed by even the most intro BattleMech. You could have a world where Mechs are actually dime a dozen due to constant output and surplus over a century or two of really low brushfire conflicts, and numerous merc bands can be found on any planet along side noble retinues and rebel idealists. And, you can even have a world where everything is scarce accept where things are hoarded at the capitals.
But, if you go the multiverse route, each would have to be supported in some fashion, if only with a blurb at the start of the Campaign Ops: Supplemental and some suggestions on how to style your campaigns off each different Universe.