Here's what I know about this:
Yes, the graphical bug on tank impacts gameplay unlikely any other graphical bug. However, I believe that this appears different to different people. Razengan has commented on people bugging tank a lot to me, however I myself have never seen the bug, of course I'm sure it exists, but to some people it'll appear normal, to others, it'll appear bugged.
My second theory- Ping will affect whether it looks normal or not. I believe this is the case for the undead bug as well. Some people will see it normally, some will see a corpse. Razengan has always had a high ping, in the 300s or more.
All the people razengan has complained about bugging tank have green pings (Dino has always had a green ping, in the 60s for an example).