Bill Tindall, E.Tn.
I prefer to assemble the entire piece at one time. This strategy enables all the joints to wiggle into submission to result in the whole coming together square and plumb. If I assembled the side panels and let the glue dry before continuing I have no assurance the mortises and dovetails for the front are orthogonal to the sides. There is no straightforward way to make the measurement. Better to avoid the risk.
So how does one proceed to assemble 60 joints all at once?
The whole of it is dry fit. In this dry fit assembly joints must slide together by hand pressure, and if not, correct the situation. A written steps of the assembly is recorded that becomes the assembly plan when gluing. Padded clamps are preadjusted for their position. The white piece of paper in the picture is the assembly instructions.
Parts are labeled for orientation so no time is lost assuring what goes where and what side is up. Parts are laid out as they will be put in place.
Use liquid hide glue. Long working time. Lubricates slide together joints.
Drawer dividers are dovetailed. This joint does not have to be clamped.
1.Rails on top and bottom of veneered side panels glued in place with legs dry fit to establish rail's correct orientation. This step could be reliably done before hand.
2. Glue all the side panels into outer and inner legs and clamp to snug joints.
3. Glue dovetailed drawer dividers into assembled side panels.
4. Add the outer leg assembly.
5. Add the top drawer divider front and back with its dovetailed ends and bridle joint middle.
6. Use a clamp to snug any loose joints.
7. Add clamps to any joint that does not want to stay snugged.
8. Do all this on a flat surface, in this case an ancient oak office desk.
PS- a wife skilled at glue application and clamp holding is beneficial.