The amount of time that the Panther will take to accelerate and match the Churchills speed and overcome it is about ~2 seconds and some change. This is also not even touching at the fact why are you chasing a Churchill with a Panther you ponce he's got 2 6 Pounders waiting to slap your ass.
I hope this points out to you the issue is you shouldn't get a tank with one of the best acceleration values into the entire game, the best health in the entire game, the ability to throw gammon bombs at people with regular grenade timers and larger AoE, ect all for just 150 fuel.
Once again because logic is somehow lost on you.
It doesn't matter if Churchill accelerates faster if can only reach a fraction of the speed of a Panther as in this example.
To put it simple: It's like comparing a car that can accelerate rapidly but can only reach 30 mp/h to a car that accelerates a bit slower but can reach 100 mp/h.
For the purpose of this demonstration lets ignore the fact that Panther can basically park in front of Churchill and laugh cos it won't be able to do anything to it.