With a good band with good musicians, there will be subtle speedups and slowdowns from each of the instruments at various times that create something that sounds very natural and very human. The drummer must have great timing to pull this off, but if does, the band will sound more real for it.
If the drummer isn't great, you'll probably want to put him on a click track to make sure that the groove doesn't fall all over the place and ruin the song. Once the drummer is happening, there is no reason why a guitar player can not sound great playing live. In most cases, there is no reason why you can't get great guitar sounds right there on the spot with just a single SM 57. A great guitar tone will be picked up just fine with a 57. I realize that some tones do require additional tricks and most home recording rigs do not have the capacity to nail this type of tone when you already have used most of your resources on your drums. Either way, if you can get a properly recorded guitar track live, by all means go for it.
Maybe you've used your fancy preamps on the drums and all you have left is cheap preamps. Do yourself a favor and wait until your hear the sound on your monitors before you decide if you need to do something different. I did a project recently (with a great band who focused on how they sounded and not on how I made them sound....which doesn't happen by the way) and when the project was completed, I received a number of compliments for the guitar sound. It turns out that the guitar was recorded live with a 57 into a cheap Mackie preamp. I've had guitars that I've recorded with my Vintech 1272 (which is supposed to be great on electric guitars) and have not received any compliments. In other words, you can get good distorted electric guitar sounds by recording live into a Mackie preamp.
Another great element to recording guitars live is the bleed factor. If you can get some guitar into the drums, I encourage it. You don't want a ton. But if you can get enough guitar in there to add a little real reverb, your guitars will sound better. I've had projects where I mic'd up the sound of the drum and guitars and was bored by both sounds. I've taken an omni or figure 8 mic and put it about halfway between the guitars and the drums. Several times this has been the difference between total crap and totally awesome. You'd be surprised!
I mixed a project yesterday in which one of the guitar players missed his footswitch when switching to the distortion channel going into the verse. This wasn't an exploding chorus, but it did pick up a little bit in intensity. He strummed the clean channel hard (when he missed the footswitch) so he waited to hit the distortion pedal on the next downbeat. It added a amazing element to the chorus and took it to another level. It's one of the best accidents I've ever recorded and it would have never occurred if we were overdubbing the shit out of it.
My point is that recording electric guitars does not necessarily sound any better simply because you put them in a different room and use better preamps. Sometimes you can record your guitars ?wrong? and come out ahead. A healthy amount of bleed, cheap preamps, and figure 8 omni mic halfway between the guitars and the drums may be all you need to capture a guitar sound that gets you lots of future business.