Virgil Johnson
I'm all for training wheels if they help getting started. Some could find clamps useful for this operation or think they could need clamps for this operation. I predict the clamps will become vestigial after a few drawers are made.

Discussions like this are fun. 8 drawers later and these clamps ain't going nowhere. As for considering these training wheels would not a fence as you describe be the same thing? Cut your dovetails at a right angle to the bottom edge and use them to align. The crappiest joints I cut on this project (there are a few) are not out of square enough to be noticeable. If this last cup of morning coffee washes down my pride I may post a pic.