A good source of consistent skill proc would be any of the Knights with the 1.28-1.36x proc based on their skill level, some of which are RG Knights. In particular, Black Locust/Robinia has 25%/40% crit chance/damage, scaling skill proc and 25% attack (plus two abilities that only activate after crushing a pest nest but they can't all be winners).
Robinia is an event Knight too so there's no need to play the odds in a gacha in order to pick her up.