In general, you build your DPS so you're spamming one key.
Given your DPS is one button spam, it doesn't really matter what you're playing since you'll be spamming the same button.

If the classes have a cast time, you spam away and a lot of the clicks are wasted... but its still decent DPS.
If the abilities are instant, the spam continues.
Either way, you spam a key for your DPS.

You manage the positioning of your toons.
Their facing.
If they're on follow or have broken follow.
If you have melee, the IWT and possibly the breaking of movement, to prevent run-offs.

You manage the tanking toon, if you have one.
If its PvP, you manage trinkets.
Irregardless of your focus, there will be a few cooldowns to manage, the more so the stronger your boxing but the more complex and harder to play it.

You also manage your healing, if you include a healer.

In general...
If you have melee and ranged...
You're still running the tank, using a Repeater Region to heal and spamming a key for the DPS to do their thing.