How come Aarindarius didn’t warn Vaarsuvius against hir specialization choices?

[Peelee]

Possible but that would make it more unlikely for Aarindarius to be able to show up and deal with the Ancient Black Dragon in the likely unworkable alternative plan - and so more likely that Vaarsuvius would have picked up on that the fiends were playing fast and loose with the truth.

If only some super good looking dragon secretly already covered that scenario.