When was the last time you saw a t3 hovertank on the field?
Cataphract: starlight with less range less dps and bigger hit box. The whole point of the starlight was long range high dps. You've just taken that away.
Lunkhead: what feels like double the cost of a tiger for what? The same hp worse speed and slightly better range and dps?
The range is already offset by the fact your hull extends out further meaning you can be hit from further. And it feels like your even weaker as every tom duck and Joe is gonna be taking shots at you and hitting your big hull.
How to fix? Make them feel like t3 units! Up costs and increase hp and dps
Make the lunkhead have a faster reload to feel more like mamoth and less like budget starlight
Big model makes players instinctively think that these are powerful tanks not to be messed with. Leading to more aggressive playstyle which causes death.