I’m a long-term RTS enthusiast and as such not only have I played the various games from the Ages franchise, but other ones as well. Among these, Warcraft III has a very interesting quality of life feature that I’m honestly missing for Age of Empires II.
When you’re selecting a group of units or buildings of different types, the game automatically “highlights” within the selection the very first type and displays its related skillset (this means the rest is still selected and a move/set rally point command would apply globally). While having this group selected and pressing Tab, the highlight switches to the next type. This would be a great introduction to my eyes, as it makes it easier to handle the frenzied macromanagement the game is all about and is much more convenient than holding Maiusc and then select to sub-group you’re looking for.
As of now, if you have several production facilities, in order to properly deal with them on a good level you’re kind of forced to assign each type of building to a specific control group, so for example you could use group 2 for barracks, 3 for archery ranges, 4 for castles and so on. The suggested implemention simplifies this system by allowing players to make a single group for all the buildings. When you select this group, you can start queueing the unit production from the barracks and then immediately switch to the archery ranges by simply pressing Tab. This setup might not only be convenient to many, but potentially would allow to reserve the control groups you would normally spend on buildings for something else. As of now, by making a single group of buildings you can only place rally points and produce units from only one of the building types.
When it comes to group of units, a similar reasoning is applied, although I have to say it’s less impactful to the game dynamics. By controlling for example a group of skirmishers, catapults and villagers, assuming skirmishers are the highlighted units at first, you can then tap Tab once to switch to the catapults to issue them an attack ground order (in fact the garrison skill belonging to the skirmishers gets replaced here by attack ground) and then Tab again to let the villagers place a castle. Of course, you can’t do this now either because you’re stuck with whatever you’re given by first selecting the group.