The M4A3 (105) at 3.0 is a massive menace to 90% of vehicles it faces in downtiers, however it can’t really compete with 3.7s, namely Pv.IV.
My idea is give it a dozerblade (mainly for added protection)
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Also also a flamethrower. Could be either a coaxial flamethrower, or one mounted above the co-driver. Heck, it could even get both.
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Then move it up to 3.3. This would get it out of 2.0 battles, but also help it in uptiers. The dozer’s added armor would make it harder for things like Pv.IV to take it out, and the flame throwers would mean you don’t need to waste a shell’s reload time on open-tops.
It would also just make it really unique.