1, Night Fae. Don’t think there is a contest here. I wouldn’t want to get on the bad side of the Winter Queen. Despite the drought they are the only covenant that remained strong and whole, dealing with threats to Ardenweald quite well.
2, Venthyr. Now that Sire Denathrius and those loyal to him have been dealt with, they have so much anima at their disposal which can be used to create literal armies of Stoneborn. They possibly have access to every other plane of the Shadowlands via hidden mirrors. Master spellcasters and infiltrators.
3, Necrolords/Maldraxxus. At full strength there is no doubt the Necrolords would be at the top, but they are far from it. The Primus is missing, and most of the high houses have been decimated by civil war. The few that remain are strong but they are a shadow of what they used to be.
4, Kyrian. I’d put Kyrian higher only they have suffered as of late due to crippling civil war, their resources are stretched and frankly they can barely defend their own lands from invasion. A large number of them also defected to the Jailers side. Not to mention the sheer incompetency from their leader the Archon.
This is my list based on how covenants currently are
It’s safe to say that all of the covenants have been diminished greatly, some more than others. It’s hard to tell who actually holds the edge.