ok, doesn't look like excessive lag, I presume we are talking fractions of a second here (or there is a problem)

Basically you get used to it, it is a bit like playing quake on a US server in the old days... I was on Pipex and still had 150ms ping... had to lead targets and hope they kept running ;)

Basically you can learn how long it really takes for your guys to stop running and cast at that point, lag spike might mess you up but generally it works fine. You watch the screen then they will run into position then cast the spell.

The same is used when chain casting, you don't wait on your main for the guys to appear ready. remember that you can use the latency for your main too and
anticipate when a spell can be cast (maybe dl quartz)

remember each character receives the keypress at the same time and so stops (unless following) turns and casts at the same time. don't let latency slow your casting time down.