I dont remember seeing a wave of complaints about the M18's lack of armor. I remember seeing people, me in particular, saying it will have very thin armor (as in M8 thickness) and it wont take much to disable. I was spot on. In terms of the Churchill's top speed being 15mph, that will keep it parked in the hanger more than you think because other than in the MW arena, it is at best equal in firepower to the M4/75mm and T34/76. The Churchill does offer up some impressive armor that rivals the Tiger and King Tiger, but other than that nothing. No pivot in place ability, no pintle MG, no added ability to traverse harsh terrain (in AH, anyways). So perhaps not "pointless" as I said at first, but certainly questionable, imo.
The same questions that was brought up about the M-18 is basically what you are implying. Yes it is slow, however its armor value makes up for it same as the Speed makes up for the lack of armor the M-18 brings to the fight.
No Pintle MG? It comes with two Besa machine guns - if you forget the PanzerF doesn't come with a pintle either, and it gets used more then you think lets not forget about the T34.... also No ability to travel harsh terrain? neither can the T-34. Either case - The Panzer F And T-34/85 get used far more frequent then you want to think.
My point is: there was plenty of doubts a no armored m-18 would last in the main arena - a few 303s knocks it out. However it has its place, and so would the Churchill tank.
You might be misunderstanding me, Just because I believe it should be added, doesn't mean I'd vote on it over a number of tanks I feel should be added first hand. For example the Crusader and Panzer III would fit nicely for midwar and early war. The Churchill tank would be nothing more then a filler for the late war arena, however it still deserves its spot in the roster eventually, given the time frame for adding equipment to Aces High - this could be years down the road.