I am not experienced at all in playing steel or dobro, let alone in a combo situation. However, quite a few years ago I played six-string in a 5-piece band. Up until that time, I had mainly practiced and played alone, or messed around now and then with another guitar player or two.
This may sound like an overly simplistic answer, and it may even seem more than obvious, but I would say not to worry so much about how to learn to back up others and whether a dobro, fiddle and bass will work together.
I say this because, at least in my experience, a combo setting is very condusive to learning and you will learn a lot about back up and other playing techniques simply by playing with a combo, trying different techniques, and listening to suggestions from your combo-mates as well as to what they are playing.
As long as you're enjoying it, I think playing in a combo is a great learning experience -- take advantage of it and have fun! I hope I get the opportunity again some day. [This message was edited by Tom Olson on 14 January 2001 at 12:58 PM.]
[This message was edited by Tom Olson on 14 January 2001 at 01:01 PM.]