So Cybran's hives are a very strong unit, UEF have engineering stations which is a good alternatives for UEF. However Aeon and Seraphim do not a good early hive alternatives . Seraphim and Aeon SACU with the Rapid Fabricator is a good late game replacement however quite costly and slow. So they really have to depend on engineers resulting in having lots of engineers surrounding building causing bad path finding.
Now I do not like the idea of Seraphim and Aeon just getting their own hive building as I like the diversity in the factions. Also I am not sure on what is possible so here are some ideas.
idea 1
Be able to combined engineers together.
So if you had 10 engineers of the same tech level you tell them to all combine together, now you have 1 engineer with the power of x10 engineers (maybe even give them a bonus boost as well), limit the max amount engineers that can be combined together. (Kind of like creating super engineers) could work the same way as a transport ship.
idea 2 when engineers are assisting they then allow units to passthrough themselves (not enemy units though) this removes the pathfinding issues and allows units to stack while assisting.
Idea 3 make hives and engineering stations T3, however this is not going to be a very popular change and I do not think is solves the issue.
So I am not sure on what is the best solution but I think both Seraphim and Aeon need something a little extra vs the hive/engineering station.
What are your Ideas and thoughts.