There are a few features which would improve a few areas where the game seems to fight you as the player of Mongols.
Packing a building should still be possible when at maximum population.
This is currently prevented and causes a lot of cumbersome interactions when trying to move buildings around late game. The player needs to clear all of their queues for unit production and then delete a villager or random unit in order to pack their building. Clearing the queues is required because otherwise you will be at max population immediately after “making room”. I understand that the reason why this is currently prevented is because a packed building counts as a unit. However, due to the nature of how packed buildings are used and the awkward interaction otherwise, this should be changed.
My suggestion is that when the player is at max pop, packing a building should not be prevented and instead allow the player to temporarily over-cap. This would would mean that they would be at 201/200. If they packed a second building, they would be at 202/200. This would fix the awkwardness and needing to clear queues while respecting the current queues.
Unpacking a building should not be interrupted by friendly unit pathing.
Currently, when the player places the template for where the building is set to unpack, the packed building will roll over there and then attempt to unpack. If units are within the template, they will move out of the way and then the building will try to unpack. If any other units path into the template after this initial check, it causes the unpack to fail. I have gotten into cycles of attempted unpacking where I have to try 3-5 times before it actually works. This is particularly a problem with the Steppe Redoubt landmark because the player is encouraged to move it to untapped gold nodes alongside their 20 villagers or so which are on the previous node. Rather than having the villagers idle, I rally them onto the new nodes and instruct the Steppe Redoubt to unpack next to it. This causes the awkward unpack dance almost 100% of the time. The only way around it is to micro my villagers out of the way specifically. This micro is not really “skillful” and is more of an annoyance than something that a player should learn.
My suggestion is that when a friendly building template is placed, friendly units should act as though the template is already filled. OR when the building attempts to unpack and the initial “scoot out of the way” is performed for units in the way, at that point; friendly units should consider the area filled and path around the intended unpack site.
Conclusion
These changes do not necessarily improve the power of the civ, but instead make one of the more complicated civs a bit more accessible by limiting the micro and awkward interactions of certain situations.