What examples are you referring to?
Why are you only bringing up those three who use to be vice admirals instead of the ones we got currently?
Because in my posts I wanted to prove that VA grade was an incredibly wide one in terms of power: it went from people that were super top-level or near top-level but didn't want to become admiral or couldn't do it because, idk, there weren't any spots at that time or weren't at that exact level yet.
We have already talked about Garp and Akainu, Aokiji and Kizaru when they were VA, but another one it's Tsuru: and old Tsuru made Doflamingo flee while Maynard was badly beaten by Barto.
It's just a grade with an incredibly wide range of power levels.
I'm just talking about the vice admirals in the present not the ones in the past.
That is another matter.
We have just said that VAs could be incredibly strong or fairly weak, it depends on the individual. In the past there were incredibly strong VA, but now?
The answer, IMHO, is debatable.
Garp and Tsuru obviously are still alive, but apart from them who can be a reasonably strong individual? Maybe the admiral candidates, we don't know how strong they might be, but they were candidates for the admiral position. Sentomaru is another possible very strong VA: Vegapunk's bodyguard, at least a Ryuo user, knows Kizaru well (maybe he trained him?).
Also, Oda has just introduced the "zodiac VA" so to speak, so some of them could be really strong. And obviously, Oda could always power up some other VA like Smoker, we simply don't know.
So, to summarize: In the past were there some strong VA that could take on Warlords? Yes, there were. As of now are there any VAs capable of that? Maybe yes, maybe not; it's debatable and depends on how strong are the Admiral candidates, on how strong are the other Zodiac VAs, etc.