I apologise for this delayed response.
Vegetto absolutely cannot tank those Ghost Kamikazes. He was barely able to speed blitz them. He’s 1.33x the Ghosts and if they hit him they’d at least do some damage.
Any statement like him barely being able to speed blitz or tank (anime only) is a suppressed Vegetto, which is proven by him stating he hasn't been serious after. You put far too much stock into earlier statements, which you use to interpret the series in ways the guides (and the series itself) don't support.
Vegetto is one of the most overhyped characters ever. Gokhan is head and shoulders above him.
Old Kai states that a Potara fusion between Goku and Gohan would not need to transform in order to beat Buutenks:
A Potara fusion of Goku and Vegeta is stated to be the strongest combo, or the amalgamation of the strongest combo:
Daizenshuu 7:
DB Forever:
It’s also stated that a potara fusion of rivals has a greater boost than normal:
“しかもライバル同士が組んだんじゃそりゃ最強にきまっとるわい”
“Further, since they are rivals, of course they are the strongest!”
DBZ Dragon Box Fact File #46:
El Manga Legendario:
“Goku and Vegeta have a very high fighting strength, but they are also very aware that they are rivals. Especially Vegeta, who was once the prince of the Saiyans. This rivalry between the two served to further increase Vegetto's strength. If Goku and Gohan had merged, it is likely that they would not have reached such a level.”
Also Goku/Gohan Potara < Goku/Vegeta Potara
So
Buutenks =< Gokuhan < Vegetto
This is shown in the anime when Vegetto stomps all over Buuhan in his base form btw, which you have no way to explain if he's like 1/40 buuhan's strength.
You can also use guide statements that imply base Vegetto (even in the manga) > Buuhan.
Daizenshuu 2:
In chapter 503, he only appeared in base form.
DB Forever:
Vegetto is the strongest warrior. Then after merging, he can
also transform. This can reasonably interpreted as he is the strongest warrior even before transforming.
Overhyped? Underhyped actually, going by your opinion. And interpreting Vegetto as barely above buuhan even in ssj, is contradicted by the series itself, and is absolutely not conducive with guides.
The preponderance of the evidence is on the side of Vegetto being stronger than you say.
