A tank that combines mark target and heat rounds does not sound like a good idea...
*Laughs in 2015 Commanther* The days when Coordinated Fire had 50% damage bonus were a terrifying one for allied tanks. I distinctly recall a situation where I was outnumbered 3 or 4-1 by Comets to the Commanther and they were scared off after one was killed during a slug-out. I'm sure allied players complained massively about C.F. 2015 being OP which is why the 25% version exists today. That and 320 -> 260 frontal armor means that its armor can feel like paper sometimes.
Now, I can do the same today with C.F. but I can't make that ISU-152 vaporise quite as quickly. I also don't see the fear in 4v4s any more.
Commando Panther is really not worth the price atm and the unit has an identity crisis.
Thats why i really like Itaperuna's idea of making the Commando Panther a real AT specialist.
Take away the aura bonus and redesign the unit as "Panther Ace".
You have good point in saying that HEAT rounds AND mark target would be too much though.
What i would like see would be an ability that would give better reload times for the Panther.
Lets gather some ideas here to make the Commando Panther better, maybe some of them can make it to the comming patch.
Another option: Spotting Scopes
The Commanther does not need a spotting scope bonus as it has 50 sight range by default - which means that if it can see you, it can shoot you. It also sees further than most TDs by standard. It is difficult to overstate the value of having 15 more sight range over the standard Panther. TDs struggle to hit you in the Fog of War while you have perfect sight on them. Ambushes become almost impossible to do, and the usual infantry blob run up simply does not work when you get early warning of them coming. An ***hole using a tank to bodyblock your tank and to make it lose sight of that (reversing) Katyusha? Doesn't happen.
However, at the end of the day it has the worst direct veterancy gains, has a very pricey fuel tag and on its own will struggle in the hands of all but an extremely experienced player. The aura is fantastic....but of limited use until you get a second vehicle (Panther) to join along. That's asking a lot for the most fuel expensive faction out there.
tl;dr I think the Commanther's in a good place right now.