If anyone is still listening, I was thinking about this thread last night. While what I said above about being on the same page is 100% needed, you also have to adapt to the circumstances involved for specific purposes. Example: while I expect people to show up knowing the songs and knowing their parts when practicing songs we've already done or at a 2nd or 3rd practice, the first time you practice a new song is the time to sit and work out everything. Tempo, structure, are we adding to or subtracting from the written music, who's playing what solo, how many measures is the solo, etc. All those things are worked out at the first practice on a new song. By second, it should be play through with minimal stops for discussion, and later that session it should be play through as you'll perform it. Then any practices afterwards you should show up ready to play your part perfectly.
That is how we've always done it. But that applies to doing things "our way." If you're going to play it exactly like it's written, or exactly like the track artist, then yeah, show up the first time ready to play. But we're always adding a tag or chorus or solos or whatever, so the first run throughs are getting down HOW we'll do the song. I usually show up with written music printed off, and then my notes on it in blue ink are what WE do to the song. And I've said before, I either don't take music on stage at all, or do ONLY so I can follow my blue ink notes, and not to "read" the music.
YMMV. Do what works for your band and situation. Consult your physician for erections lasting over 4 hours. And let me know how you pulled that off (no pun intended).