This is one alliance's recommended ordering, not a confirmed game mechanic.

• Development first. Auto Rally, then Fast Build, Enhance Help and Gathering Speedup, then the three resource outputs. These affect every member every day.
• Then Development 2 and 3 — Research Speedup and Upgrade, the three resource protections, Crafting Speedup and Technique, Construction Cost.
• War tree from the start, but shallow. Troop Load, then Fast Training, Coordinated Training, Gathering Speedup, March Aid and Quick Garrison. Then rally stats, then garrison stats and Barracks Expansion.
• The actual advice is to alternate. Take the first Development group to about level 3, unlock War levels 1–3, then alternate — when a long research is running in one tree, run quick ones in the other. This keeps donations from stalling.
• Long term, max Development before investing fully in War.