Perhaps the plans in 80/20 Running by Matt Fitzgerald would work. The level one plan has one day off per week and three days of cross-training (or easy running.) I’ve found that, as I have aged, cross-training works better from me than running too much and getting injured.
I think running lots would be better for getting faster, BUT you can’t run lots if you are injured. Second best is a structured plan incorporating cross-training.
Sounds like a really good suggestion and way to proceed.