Maybe once upon a time the KV1's armour was foolproof, and the IS-3 was considered to have a good turret, but that's just not the case anymore. Basically no tank in this line has foolproof armour except the IS-7 at Tier X. The KV1's armor is a joke nowadays with it's turret being penned frontally by it's own standard rounds.
I think Newcomers would honestly be better served by something like the E-100 line nowadays, with pretty much every tank in the line being good, the Tier 8 actually being useful hulldown with the Cupola of the Tiger II being harder to hit than the massive 50mm roof on the IS3, the E75 is basically the foolproof tank noobs need with the ability to play hulldown, sidescrape and the armor being pretty foolproof.
Alternately, British heavies, while they may be pretty bad at the start, every tank from Tier 8-10 basically plays the same way and is really good at it.
Even Swedish Heavies are more foolproof to play from tier 8-10 than the IS7 line.
IS7 is probably the best Tier 10 to give to a noob, but not sure if the line is actually good for them.
Source: https://www.reddit.com/r/WorldofTanks/comments/ubaj4r/unpopular_opinion_the_is7_line_shouldnt_be/
