I typically do lower body strength on my workout days so I can keep the easy days easy, though this can present some challenges.

If you don't want to do all the hard stuff on one day, I would recommend doing leg strength AFTER a hard running day rather than before so you're not compromising your run.
Right now I'm doing more cross-training thanks to an ankle strain that has been taking FOREVER to heal, but typically my schedule looks something like this:
- easy + core
- workout + lower body
- easy + upper body
- easy + core
- medium-long + rehab/mobility
- long
- off (sometimes yoga)
There's some overlap between the rehab and lower body strength exercises, but rehab days tend to be lighter weights and more focused on range of motion/reps for me.
Mostly I do about 30 minutes strength sessions, maybe a little shorter for core work (not including any additional warm-up/stretching). I also do calf raises on every strength day after having multiple lower-leg tendon issues.