Actually it isn't. The problem isn't the unit, but the combination you use.
you obviously aren't able to read the question properly and are here just to troll, I strongly advise you to find something to fill your spare time with except trolling on these forums, as in reality, no one is asking for opinions of a player who has 6000 player points and is in Bronze Age...
my TF Stealth Tanks with a 680% attack boost from my city able to kill SAAB defense units, how is that a problem in the combination I use? I'm using the right combination and I'm massacring units of an era that is 5 eras above TF ... you call that a balanced approach? every unit in every era has a higher range then SAAB units, if you knew anything about how the defensive mechanism works, you wouldn't be talking nonsense here, and would stay quiet in a corner like a troll you are... let me give you a lesson on how defensive mechanism works
the defending units focus the closest attacking unit that comes into range
every unit from CA+ has higher movement speed than a rogue
so the main unit will get faster in range to the defensive units then a rogue and the defender units will attack the main unit first, and kill the main unit first, and then they will 1 shot the rogues because rogues won't have anything to spawn in to
that being said, in my above screenshot, even with the fact that that unit was damaged when it started the battle, and the fact that that unit went straight forward into defenders Archers, SAAB units are 16 eras above Iron Age units, and in reality, the Archers shouldn't even be able to do 1% damage on them, yet alone kill the entire attacking combo ...
now please, do us all a favor, and go learn to play the game first, then come and troll