Max one or level up equally?

[FelipeXIX]

If I have buildings with several levels to upgrade after advancing, is it better to max one of them first, then do the others or level them all up one level, then start again and level them all up to the next level?

I know garrisons and tank depots have an advantage to max one first, but does this hold true for towers, anti-aircraft and the others?

 

[Chartlux]

Buildings
Armory and House: Command Post(Resistance)
Factory: Bunker(Resistance)

Units
Machine Gun: Machine Gun Infantry(Counter Offensive)

 

[King Crimson]

If there's a weekend sale with a particular building type that needs upgrading, Personally, I try and upgrade 3 or more in the one weekend. This way, when the buildings finish their upgrades together, my base will be stronger in numerous places.
If I only max one building at a time, people will likely attack my base where the buildings are still at their lower levels.
Hope this helps.