1.why is cost irrelevant ?
2.I don't care if it's an AC in real life (i don't find killing machines aka weapons as fascinating as most people in this forum so i don't know anything detailed about this unit). INGAME it costs more than a t70 and as you said the t70 is a light tank so the puma should also be classified as a tank and not an armored car.
1. Costs are always releveant. Farther up in the thread someone stated that it was OK that the Sherman is more expensive since it is a call in. But then the Puma is compared in cost to a T70 even though it too is a call in and doesn't require tech.
2. True that what they are called is less relevant than how they are used. As people get more comfortable with uses they will start to see the units for their use as opposed to their look.
Much of the look/ability of German kit is to please the multitudes of German army fans out there. That is why so many units show up in games even though they never appeared in anything but token numbers show up in WW2 games. Just get used to it as you have to live with it.
(Only 40 Ostwinds were ever made, 60 Elephants, 100 Pumas with the 50mm and 200 with the 20mm. As opposed to allied units you never see which were produced in the thousands, like the m10 Achilles, m36 Jacksons, and artillery out the wazoo. "Out the wazoo I tell you!")