The pack howitzer is absolutely broken, probably the most OP unit in the game. The damage each shell does is just disgusting and it completely out of proportion for every other unit in its class.
Not really, Leigs are also quite annoying and so is the HM31 when it miraculously lands shells near a blob and you have to retreat 4+ squads to heal (the other times it lands in another country). That doesn’t make them broken just because they sometimes work.
Pack howitzer is fine. Perimeter overwatch should be changed to a single sector for 100 muni for like 30 secs or something. Spec Ops flares should just have their duration halved. Assault should have its accuracy buff reverted. I like your mortar pit idea, though I would prefer to have a 150mp pit with 2 mortars that's like 40% of the current one's health and can't brace. Maybe it can upgrade to the current one but more durable and higher pop for 200mp extra?