How many pitchers for roto?

[Baseballer02]

Just made a transaction on one of my teams and now I think I may have made a mistake. I dropped Marlon Byrd for Ben Sheets, seeing as how he's a good #4 or 5 starter. I didn't pay attention to it before I made the transaction, but I now have 10 pitchers on my roster. 6SPs and 4 Closers. I'm thinking this may be a bit much, unless I spot start on a pitcher or two. Roster looks like so:

C-Lieberthal
1b-Konerko
2b-Kennedy
3b-Chavez
ss-A-rod
of-Pierre
of-Crawford
of-Wells
Util-H. Matsui
Bench-Hinske
Bench-Lecroy

SP-Hudson
SP-Mulder
RP-Cordero
RP-Issy
P-Graves
P-Speier
P-Webb
Bench-Sabathia
Bench-Affeldt
Bench-Sheets