I think that some of the issues are with translations between 'canon editions'
battletech canon v1: the only tank is the scorpion, there are no factories, terraforming fails regularly, raids are over water purifiers, populations don't give a fig which petty lord rules them and don't resist; everything is circling the drain and nothing gets better ever. Combined arms are understandably dead in this era, as there are no (rules for) infantry, flying things or artillery, and the single tank is a bare step above target practice.
battletech canon v2: Infantry are a little dangerous and vehicles can come with fusion engines, there are actual nations, and things are sort of getting more stable. The house book era, basically, with citytech (Vees and infantry added) and aerotech
Battletech Canon V3 - 4SW happens, clans return, power armor and warships appear, other stuff gets backfilled. But there are holdovers from era 1- populations still don't resist unless they are massively provoked. This makes no sense, people argue about it endlessly, and canon eventually gets a retcon except for the bits seen on screen.