It all depends of Lucas' own definition of "compete". When he stated that Windu can compete with Sidious, he was compering his performances to Kolar's, Fisto's and Tiin's.
According to Filoni, even Savage's performance against Sidious was superior to theirs. So, there might be assumption, that Savage and Maul can compete with Sidious as well.
__________________ "Happiness is a lie. Life is horror. The light is always dying all across the universe. The last star will flicker out someday, when it does, all that remains is shadow. And I will be its king!"'-Amahl Farouk
Still allright of we are assume that he was toying with them. Which was actually true.
Other example, Kenobi could compete with Dooku for sure, but he was far from being his equal.
Toying with them or not is irrelevant tbh because it was a very one sided fight as it was.
Don't really see how Kenobi ever competed against Dooku tbh. Neither of them ever landed a single hit on Dooku despite having aid from a much more Powerful combatant than himself.
Same with Ventress vs Dooku. Clashing blades a few times, or putting up a bit of a fight, before going down is not competing IMO. Fact is Ventress was no match for Dooku without Opress's aid, as Dooku correctly pointed out. So again it was a very 1 sided fight, and was just about how long Ventress would last before the inevitable happened. And again Ventress wasn't capable of landing a single hit on Dooku.
Whilst Dooku easily evaded her attacks, and Landed multiple kicks flooring her. And in their 1 v 1 he took her out in a short time.