I think that is good advice. 3 on/2 off was always one of my favorite sessions to get my running fitness up
I would make the flat efforts longer, even if that means running 3 min, walking 1. You shouldn't underestimate how much benefit you will get from time spent on your feet.
I would keep you strength training at maintenance levels and concentrate on METCON. I certainly wouldn't be pushing too hard on Deads and Squats while you bring your running up.