On line balloting seems a bit extreme, but yeah, just discuss.
In addition, does it work for the band. Lots of people pick stuff they can't play well, especially vocally. You can deal with a missing guitar line, but vocals is what people recognize (Including if there are backing vocals) Don't pick Journey or Boston if your guy can't hit the notes, as an example.
There are a few songs that I will refuse to do because I know we cannot pull of the guitar lines (I'm one of the guitar players). I was the bass player previously and they wanted to do stuff like Comfortably Numb and I said it's a downer and you can't play the leads correctly, lets bag it. For some reason now other guitar player wants to do Sweet Child of Mine , I think only because he's painfully learning it from his guitar teacher. I don't think that will fit our vibe of country and some tired classic rock, so it will inenvetably come to a decision, but for right now no big deal.
I try and push in the direction of 1. recognizable (same guy tried to pull some brand new country tune that would be a hit this summer) 2. easy (we all have jobs) how much effort do we need to put into this so sound competent? How much effort CAN we put into this? Each of us are like a superhero we all have a tragic weakness, myself included. This will change over time, we're a group of 40-50 year olds and some have never played out before this group so the potential is there to bring more intricate stuff in as we further gel.