(despite the sump "pit" not being quite deep enough for my liking) .
I suggest a pit with at least 3 cubic feet (a little over 20 gallons) below the rims of the perimeter drain pipes. An 18x18 inch square pit (clear space, not counting a brick lining or gravel fill) would need to extend 16 inches below the drain pipes. The pit may be close to the wall even though it is much deeper than the foundation footings.
This allows longer pump run times and fewer on off cycles. This allows more time for already accumulated water in the drain pipes to make its way to the pit before the pump shuts off, if the turn on level was a bit above the drain pipe rims. This reduces the impact of water in the outlet pipe falling back down if the check valve did not seal completely.
When cleaning anything including baby diapers, it is better to sweep off or scrape off as much solid and semisolid material as you can first. (1) Less cleaning fluid or detergent needs to be used, (2) Less of a mushy mess which in turn means that bleaches or disinfectants will be more effective.