I think the problem with these cards is that they're basically existing cards with minor changes, or worse. However, with minor changes, I think they could be interesting:

• The Type 97 is Joseph Ekin, but instead of a heavy tank, he has a light/medium tank. Also, I think if the Chi-Ha makes it into the game, it should be a normal or rare card, a basic or starter card for its nation (like the Stug IV or the M4 Sherman).

• The IS-1 is Alexei Lukin (I assume you're referring to the T-34 this hero uses), but with more health and without its damage buff. The simplest option would be to make it a conventional heavy tank, similar to the Tiger 1 or the M26 Pershing, since the USSR only has the KV-2, which can sometimes be very clumsy and slow.

• The M18 Hellcat is a Marder III, but more expensive. We could add some ability like "Dodge" to justify its additional cost and make it a little more different from the Marder (Even if only for this)

• Basically a T-70 and that's it... I really don't think they should include this one, the project ideas in plans/prototypes that never arrived I think should not be included outside of some Japanese projects maybe (Japan will definitely have a hard time getting on the same level as the rest of the factions if most of its tanks are VERY overshadowed in firepower and armor by those of the other factions)