A command stand and a couple of regiments and you're good to go. Brigades went from two to maybe six regiments of varying sizes. If you've not done skirmishers yet, just don't move into skirmish formation.
Generally, one skirmish base per regiment is more than enough. Most of the time you'll remain in formation, but having enough bases to take up mixed formation with the whole brigade could be useful to protect your line.
Cos then I don't need different bases - they're going to represent a battery anyway, and you don't take models off as casualties. So they're going to cover that space anyway, most likely, so why not put them on one base?
I'm not married to the idea though, and I don't have any artillery yet anyway.
One thing about cavalry, you want them in line formation and not column. For confederates you could also be a bit more creative with positioning, similar to impetus basing.