I think what made it broken was the ability to call in a techless AI medium tank on top of having the Puma, more than the Puma itself, as this combo gave an endless supply of call-in AT and AI without ever needing to go past T1. I think in hindsight the wrong vehicle was nerfed and what should've gotten put into tech was the Command P4 rather than the Puma.
Although of course making the Puma a call-in or only require T2 would risk seeing MobDef nearly every game again because an easily available Puma simply fixes Ostheer's most glaring weakness.
You'd think, but Old Mobidef got a ton of testing as a consequence of GCS 2 and the games were often decided before CP9.
You'd go T1 into T2 as normal, then build about four Ostheer lights. Often you'd get double Flamer 251s. When the opponent eventually cobbled together the fuel for a T-70 or AEC, you'd call in the Puma and kill it. If they try to use multiple lights, call in multiple Pumas.
The Command Tank is just a nail in the coffin.
The big problem with Old Mobile Defence as a commander was its mere presence in the Command Bar means Ostheer can suddenly throw a Puma at you, and that completely changes how you play. I'm actually fairly content for the Puma to stay where it is now that Ostheer's been rebalanced around its absence.
I think the best solution is to make the Puma work in its current T2 + BP2 timing. At that timing, it competes with the StuG, so it's got to be competitive with the StuG.
There are a lot of creative ways to do that.
- Give it OKW HEAT rounds, allowing it to fight like a StuG for a munitions cost.
or
- Give it built-in spotting scopes, allowing it to scout for other vehicles from Vet 0.
or
- Give it the ability to capture points, playing into the theme of the doctrine.
or
- Make it a fair bit cheaper, making it a very cost efficient TD given its timing.