The Firefly is not cost efficient for a 1v1. It's basically a 4v4 unit when you're likely going to have an excess of resources to burn.
I don't think the firefly need to be stronger, just cheaper. I like how the Firefly handle currently. It's distinctly different from the Jackson and the su-85 and still serve the role of TD pretty well.
Nerf the tulip so the axis doesn't need to worry about losing Tanks to the firefly's alpha strike, then decrease the price of the firefly so the british can get it in a 1v1.
And since FF is SITUATIONAL unit which only COMPLEMENTS brit AT.
Stop it, FF is not intended to be useful in every matchup on every map and in every situation.
No one likes facing TD with the ability to one shot tanks. Yet, that ability to one-shot tank is the only justification for the firefly's impractically high price.
Speak for youself. Jt, elefant and pak43 were in game forever as well as pak walls. If you lost your tank to FF its not because "omg op/bad design nerf plx" its because you were outsmarted and outplayed.
FF offers counters to threats allied armies struggle to counters such as 17 target-size predator-cloak jp4 and blitz-away from everything panthers. If you take away FF ability to burst tanks in exchange for DPS increase/cost decrease, it would not become useful because you imagine it should, but directly opposite.
Besides there is zero reason brits with their beefy tanks should have jackson clone. Especially in 1v1.