There are contradictions, Takao Koyama himself says that Goku (Movie 13) is the same as Goku (Movie 12) on the Toei 2005 website, and he himself says that it is Broly a while later
So yes, it depends on your idea, but I still think it's Beerus followed by Golden Frieza (I would consider Broly...
It was in the same situation as Cell, the difference is that Goku helped Gohan, and when Gohan transforms into SSJ2 he kills them all easily (considering that Gohan had to fight Bojack and his minions)
So yes, there is nothing saying that he had difficulties in SSJ2, just that in SSJ he had a...
Gohan was already all wounded because he faced all the minions and Bojack, and Bojack was humiliated with SSJ2 I don't see where he had difficulties with SSJ2
Bojack Base ("surpasses even the Super Saiyans") = Perfect Cell (vs Goku or Gohan)
Perfect Cell (Full Power) > Bojack Full Power
Bojack is a good villain but needed his minions all the time
In Daizenshuu 6# the abyss between Broly LSSJ and Z Fighters in the Movie is explicit, not to mention that the Z fighters were revived several times and Goku had a "TOEI UP" to defeat Broly (I just think that Movie 10 should be another villain and movie 11 about Broly's return only better...
You say Super Hatchiyack?
Film 9 continues with weaker Vegeta and Trunks, what counts is Gohan in the film
But yes he was easily defeated by Gohan SSJ2
Broly (Movie 8) was defeated by a Goku (Toei Power Up) who was considered to have a ki 1000x for courage (but hardly anyone will accept)
I don't normally take Takao Koyama seriously.
Takao Koyama's comment about "the future villains are stronger than the previous ones" I don't take seriously, and he himself comments on the Toei website about Janemba > Hiudegarn (these are his general comments)
So he probably contradicts himself...