But we want to entice him into our camp slowly but surely, not drive him and his houses three dragons into the arms of Daemon
The thing about that is that Daemon would likely never kill us while Viserys lives, he loves Viserys too much for that, so even in worst case scenario where Daemon and Corlys ally to put Daemon on the throne, we have years until such a conflict, years we could use to have dragon rider children of our own, or to ally with our Westerling siblings.
On top of that, the "Loveless" marriage between Rhaneyra and Laenor wouldn't be loveless, since Rhaneyra would have Alicent and since there's no Criston with a white cloak, Laenor would have Joffrey, plus, Rhaenyra and Laenor in canon were friends, so not only would the marriage smooth over our attempts to reduce Corly's monopoly, it also would be workable for Rhaenyra.
Also i'm just not really a fan of the idea of attempting to mollify someone who might already be our enemy, since Corlys almost certainly knows it was us who got Viserys with Johanna, and he gave us a rather curt letter when we asked Laenor to join our progress, along with having been fighting a successful war in the Stepstones for more than a year now with Daemon, they might already be in a hate circle for us.
So no, I don't agree we should purposefully keep our position weak and Corly's poisition strong in the hopes we get some pity points from him, also you're underestimating Rhaenys, by the time Viserys has keeled over and the lines have been drawn, Syrax will be bigger and we'll be at the very least an accomplished warrior and even if our Westerling siblings are against us too, we'll likely have dragon riding children to bolster our numbers, so either way any war of succession will be destructive.
I doubt Rhaenys will want her children and husband to fight in a war they could very likely die in or even want Laena married to someone like Daemon, also, rather morbid, but if Daemon fathers children on Laena, she might die from childbirth like in canon and in that case, uh, Vhagar is free.