The old system implement by Relic with reinforcement time connected to entity cost was completely arbitrary was part of the reason why certain units where and some still are UP.
Imo it was one of the main issue with Pg which not only had to retreat earlier due to low entity count but also had to spend lots of down time to reinforce. Same thing now happen with Ostheer officer with their long reinforcement time.
As for Bunker imo the change that allow ostheer to build make to upgrades one one bunker is part of ostheer strength (at least in larger games). It would have been better if command bunker where cheaper and only healed garrisoned units.
