In term of pure power stats, Baron Zompeng is the weakest one. But he gains lethal ability as exchange: Poison. His Poison has 50% dose of lethality. This means no matter how high your HP, you will always die in 2 attacks from Baron Zompeng. Combined with his big piercing attack, he suddenly becomes the most dreadful Baron in the game. But you know what hard-counter Baron Peng? Curse debuff. If you remove his Poison ability, he gets degraded into weak enemy. And among all compatible Curse units, Boomerang Cat is the most accessible one.
Of course since Boomerang Cat has such weak specification, it can be difficult to set him up. You need to create good opening and hope that you can keep it up until you can kill Baron Zompeng permanently. It's one of the most famous strats, but it's also not good for farming. Until we finally get Boomerang Cat TF: Fried Chicken Cat. FCC fixes all of his old problems and change this starts to more reliable
1. FCC now has AoE and can bypass the peons spam
2. FCC has better standing range which help him to survive against peons better
3. And finally better HP. Because of his slow speed, you need to create good opening via Cat Cannon to let him reach Baron Zompeng. But after TF, you don't need to do that anymore. Your unit needs at least 6000 HP to tank one attack from Baron Zompeng and FCC can do that in Lv31.
Really. After unlocking his TF, the strats got simplified to spamming FCC until you win. No need special setup. Just blind spam. It's even Cat-CPU-able. It's complete powercreep. You have a free unit who completely trivialize Baron Zompeng and give you free access to easy Zombie Orb.
Now final question. How does this affect Envanz placement in the meta? Envanz is the original hard-counter to Baron Zompeng. But now we have free unit that do better than them, does this mean Envanz becomes irrelevant again? Well, not completely. Knowing that FCC is locked behind hard stage, Evanz can still be temporary substitution until you recruit FCC. And there is no rule to forbid using both of them. Although this definitely costs Envanz in his tier list. Expect he drop some rank after this. Rip bozo.