Wat, Strike bosses ARE literally just remodels with more health, for the most part. Any unique mechanics are very very VERY minor. The only decent unique strike boss mechanic I can even think of is echo chamber, and that was gimmicky as -blam!- at that but at least they tried something new.

Please show me a normal mob that looks like a spider tank or ta'aric or phogoth etc

devil walkers aren't even a full boss, miniboss at best, hell they're not even a mob really they're destiny's version of a main battle tank. Final mission of vanilla division has a heavily armed helicopter. Phogoth is just an upsized ogre ffs. I don't even know what you mean by ta'aric, but none of the cabal bosses are particularly unique, they are just upscaled and with random extra armour pieces added on.