Problem with hero control

I am currently trying to master Moddok Crevice on one of my characters, and I have a hero build that has, in the past, completely creamed the runners. The gist of it involves Arcane Echo + Mind Freeze. Previously, all I had to do was:
Target one runner
Tell the hero to use AE
Click on MF to tell the hero to use it next chance he gets
Walk up to the runners (hero casts at this point)
Change targets (while the hero casts MF)
Click the echoed MF
Job done
But now, my hero is only casting MF if I have a runner locked. To compound things, it seems I need to MF the first runner, unlock the it, target the second one, lock it and THEN tell the hero to cast, all before they start moving. Did Anet change hero AI to nerf this "trick" to snaring opponents with heroes, or am I doing something wrong here?

FWIW, if you use Deep Freeze to draw aggro on the runners (either manual hero-cast or yours), you'll be able to cripple them both and have more than enough time to take them both out. I usually lock my MM on the left runner and always head towards the right-most one, as he seems to get away from the pack a bit faster than the left.

If I understand your question correctly, blackmage, I believe I may have encountered a semi-similar situation that could shed some light

I test damage on rangers a lot, trying to incorporate separate spikes into HA groups, etc. When I used to test my ranger w/ two heroes, I couldn't start attacking it or the heroes would. Recently I was testing another build which was myself on ranger, 2 ranger heroes, and 1 necro hero. I click-checked each heroes skill/spell, and they did nothing...until i hit ctrl + the skill, calling it. They synced it perfectly with me...

So I think the solution may just be calling each target separately. hit arcane echo, ctrl + cast on first guy, switch target, then ctrl + cast on the other guy.

Hope this helped

Ah, that might even work better than my solution. After a bit of fiddling around with it, I think what was happening was that Zhed (the hero I was using) was not casting because, although I told him to cast, he was not in combat, so he never had a target to cast on. What I eventually did was click-check the skill while I was closing in on the runners, so Zhed was close enough to auto-engage, then switch targets and click on the echoed spell.