I think having the Puma for Wehrmacht makes for an extremely interesting commander, as it can open up unique new strategies and diminishes the extent to which Wehrmacht tier2 gets dominated by Stuart and AEC.
The call in Puma in Mobile Defense was nerfed because it was too powerful. However, the current requirement of BP2 puts it almost behind tier3 which I think makes it all but obsolete.
Here's a middle of the road suggestion:
Add an upgrade to the Leichte Mechanized called "requisition Puma", similar to the Brit upgrade for the AEC. This could be about 20-30 fuel and will unlock the Puma from tier2. Not immediately, but at a timing which might see it in action against Stuart/AEC/AA HT before tier3 hits. A Wehrmacht player could now get the Puma as an alternative stepping stone to tier4.