We tend to do the drum part first and then play according to that, using that as our cue for timing. We'll often lay guitar tracks down together and someone'll add any bass that needs adding. If it's more complex, we'll lay down individual tracks to fill in around the edges. As for fingers, mine are fairly skinny and tend to do what I tell them to do. I've got really adept wrist muscles as well. I do use a hand/wrist exerciser thing with different tensions, though it's just on high. I've got a grip like a vise. It's from decades of working at it and decades of practice. But, the fingers do what I ask of them. They're well-trained and I can cover anything I want. I can't find anything that I can't cover, which is good. Then again, if I wasn't pretty adept by this time, I should probably stop playing and do something else with my life.