Leftover staff uses after each chapters.

14 - 4 w 2 r 3 a
15 - 3 w
16 - 7 r
16x - 2 a
17 - 1 a
18 - 6 r
19 - 4 r 1 w
20 - 5 w 4 a
20x - 4 w (no idea what turncount you'll get, but you mentioned a warp due to base!Marth so...)
21 - 6 w 3 r 2 a (double again for Minerva to visit the SS, instead of expending a warp)
22 - 4 w 1 a (not sure if you need the again, I think you may be able to shave a turn with it here or on C19)
23 - 2 w

endgame is done with 2 warp, 3 rescue, 1 again.