Regular Hetzer will be 100% copy of Jagdpanzer, so what for you need it actually? Better then add there some other unit. Maybe place there Marder III as cheap version of Jagdpanzer - same power, but less HP and armor? Or, since it's feuersturm doctrine, add there Luchs 2 with flamer gun, there was such modification actually. Of course, for lesser CP.
I think the regular Hetzer would be a better idea because the marder 3 has no machine gun so it could not engage infantry but the hetzer does so it could be used as a light assault gun as well as a tank destroyer unlike the marder 3 and jadgpanzer which are useless against infantry and the hetzer would have better armor than the marder 3 but not as good as the jadgpanzer 4