Typically we only recommend 2 max strength sessions per week to allow 72 hours between. If you are doing hill sprints or other max power type training then substitute that for one day of the max for the legs as thy are the same kind of stimulus.
We normally use a core routine for the warm up for max and other strength. We do this because the core muscles are predominately slow twitch and highly fatigue resistant. For this same reason you can do core training more often because those slow twitch muscles recover faster than FT muscles.
Scott