Why pay the same price? for a mediocre unit.
Like the Panther you mean? which is not cost efficient compared to the Stug.
Its fair to compare the two as they share a similar cost and hit the field in the same time meaning engagements are bound to happen.
Using the same criteria one can compare the Ostwind and the T-34/76. One will find the Ostwind lucking.
IMO the problem is the comet doesn't have anything special about it to make it 'asymmetrical' or require some way of beating an equally priced panther. Its not closing the distance on a panther nor does flanking as a blitz can happen or you are ez pz snared. The ranges are 45 and 50 with panther having slight edge so kiting comets is easier. Panther gun has higher pen ratio to the comet 74~% vs comet to panther 51~% making the engagement more lopsided in the AT department.
Kitting Comet is easy?
Comet has an edge over the Panther is most things needed to for kiting.
Comet has more vision, more speed and better chance of hitting the Panther. Panther has over Comet 5 range which without vision is useless.
This would be fair if the Comet made up for its lack in AT department with better AI capability or had a lower price. As it stands now however. its just not a fair resource investment.
Better AI to deal with what? It can already kite AT SP, At ST and AT PG and is one of the MBT that can deal with ATG easily.
Do you actually want to turn it into a Croc or Pershing?