Absolutely there's a discussion to be had.
Surely you're referring to who is the better player right now, since ultimately that's all that matters.
Who's the better blocker? Sanu.
Who's more durable? Sanu.
Who's bigger and more physical? Sanu.
Who's younger? Sanu.
Who has an additional year on their contract? Sanu.
Who's coming off an achilles tear? Sanders.
All of these variables go into who the better player is/will be, especially when taking a macro, long-term, team building approach.
Sanders is a great player and I have no doubt he would have succeeded here had we traded for him. I'm not convinced that he'd be significantly better here in NE than Sanu will be.