You could actually give orders to every unit on the map. However, it would be counter productive to do so. Just like if you are company commander which means that you should be the most senior/experienced officer in the company. Therefore, you could give individual tailored orders to each soldier in the company, but the results would be suboptimal.
In game terms, you would pay the following penalties by giving orders to each and every unit:
(1) Excessive order delays.
(2) Lack of cohesive action by units on defense and a total inability to even contemplate making an attack.
(3) In ability to manage the big picture which is the role you have been cast in as the human player.
...
At other end of the spectrum could find the senior commander on the map and order him (meaning the entire force on the map) to simply attack here or defend here:
(1) Of course, this doesn't work if there are multiple objectives.
(2) Does not allow you to determine which forces are used best in which roles.
(3) Does not allow you to take maximum advantage of different terrain features of the battle space.
(4) Does not allow you to meter the level of casualties/fatigue you sustain so that you can best pace yourself.
(5) Does not allow you to attack along different axis or defend at various locations or layers.
(6) Does not allow you to formulate a plan that uses time as a strategic dimension.
...
So, what's my point? After all, I should have one.

Simply this ... playing (commanding) HTTR effectively is finding the right balance between micro/macro managing. This is partly a function of the dynamics of what works well in the game and partly a function of one's individual style of play. More so than any other game which I have seen, this game allows the maximum flexibility of finding a balance somewhere along that spectrum which I enumerated above. Also, HTTR allows you to within even one gaming session micro-manage one area of the battle while you macro-manage another area of the battle. It really is quite unique.
I am sorry, but I am not familiar with the game you mentioned, but I hope my explanation helped you to understand it a little better. Also, see:
showthread.php?t=44457
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