Those are especially powerful AP rounds, but as the other man said, you arent actually shooting it at the correct angle there, it should be exact to the impact angle as it would be at any real distance.
The T-10M definitely cant penetrate the UFP of the Tiger 2, The Maus also probably cant, the 278 and IS-7 might be able to however. Those extra 5 degrees make an enormous difference to AP, whereas with APDS not so much, thats one definite advantage that APDS has, and why the 84mm 20pdr APDS can penetrate the UFP even though an AP round with higher 60o pen cannot.
Low caliber low tier APDS shouldnt be especially powerful, but the high penetration actually gives you a chance of penetrating a KV-1 at all, Russian tanks at that BR have that huge breach weakspot that the APDS should be able to take out with ease. The APDS in that vehicle also has identical penetration to the mysteriously missing 57mm 6pdr APDS that should be in the game.
I have also noticed that 105mm HESH has a more consistent damage profile sometimes than HESH that is much more powerful than it… I wonder if it has anything to do with the fact that it is a multi national round and so Gaijin will actually prioritize making it usable when it doesnt involve Britain.
The Avenger is a perfectly competent tank destroyer for 4.7. The Comet should be dropped back to 5.0 as I have always found it to be a non-competitive vehicle, and now especially when its APDS is effectively just APCR now.
And the AP on the comet is awful yes, its APDS was decent enough a while back which made it a trolly hull down sniper, nowadays it cannot do that and its not a vehicle I ever felt comfortable flanking with either.

