From a positional perspective I get what you're saying. They are all 4/5s...but Nance is a much different player imo. He's a great defender at both the 4 and 5...terrific energy and disruptor. He's a great utility guy who makes impacts on games without scoring...scoring and shooting are his limitation.
Paschall is kinda the exact opposite. He doesn't defend, doesn't rebound, and hasn't figured out how to play in a team concept. Both may be iffy shooters, but the one thing Paschall can do is get buckets. Nance is the player the does a million things besides scoring, Paschall is the guy where scoring is pretty much all he does.
Gay is a strong defender, but not at the same level or activity as Nance. No shame in that, I think Nance is one of the better defenders in the league at his position. He's just a different player. I know Gay has changed up his game as he's gotten older, but he's still so much different than Nance. He's a more prolific shooter and still gets to his spots in his mid range. Gay's scoring/shooting ability made me more comfortable with trading Bogey because he provides some offensive firepower even if he's not at the same level as Bogey.
I would still do Bogey for Nance. I can see how we might be feeling a little light on scoring if you're planning to play Royce+Nance+Gobert, but I think Gay is good insurance if you needed a bigger body who can also score. I'm wondering if the actual trade would be Ingles for Nance. I think Joe is a better player than Bogey...but it's clear that Quin has Bogey in much higher regard.