Midships cleats are very useful in marinas for rigging lines that prevent the boat from surging fore and aft. These are not true spring lines however. Boat ‘A’ is rigged marina fashion, and there’s nothing wrong with this. Boat ‘B’ is rigged with real springs which have two advantages.
1 ─ Bring in all lines, then motor astern against the spring led from the quarter and the bow will lift off the dock as if by magic (vice-versa the bow spring). This doesn’t work properly with a midships spring
2 ─ Where a boat persists in lying ‘bows-in’ despite all you do, a heave on the stern spring will tuck the quarter in sweetly in a way a midships spring can never achieve.