Aokiji didn't counter Ace, they matched each other in Marineford.
If there is anyone countered by Aokiji's power it is Jinbe and his water.
It is certainly interesting and possible match-up, perhaps too much against Jinbe.
I think the more likely pairing is with Sanjino and the contest will be who can push their abilities further.
Can Sanjino heat up more than Kuzan can cool it down...
Shiryu is invisible, but his body is still solid, he can be cut. Jozus diamond devil fruit would make more sense for that comparison.
Kuzan is still a mystery and could betray at any time. If he leaves, then the next strongest is either Lafitte or Pizzaro.
Lafitte is still mysterious and he could end up being anything from:
Weak trio (Nami's opponent as navigator)
Mid Trio (Brooks opponent (Cane weapon, Angel Df, West Blue)
Wings: Sanji's opponent (Chief of Staff, Angel DF, portrayal makes him look stronger than the other original members).
If Kuzan leaves/betrays BBPs we will have to re-adjust pairings but I would still treat them the same - direct counters of SHs.
And I don't see a direct counter to Sanji among BBPs aside from Kuzan.
Also, Shiryu's invisibility is the basic ability, his purpose is not to re-use what Abasalom already has shown.
His purpose is to do something new with it and the only way to counter a guy who can cut everything is by becoming Nothing.
Your direct counter theory is a bit too complicated, I don’t see any direct counters for the other SHs.
Isnt it obvious with Luffy vs Blackbeard and Zoro vs Shiryu?
It will apply to other Strawhats as well.
BBPs are unique in that they are challenging the core abilities of Strawhats.
Blackbeard nullifies Luffy's DF-based attacks which is literally 99% of them.
Shiryu prevents Zoro from doing what Zoro does primarily - cutting.
Sanji's core ability is heat. Cold is the perfect counter, IMO.
Usopp's sniping skills are directly challenged by Augur's Warping.
All others will have their primary ability countered too.
Messing with Sanji's mind is an old trick and not really challenging his combat ability...