I think it's good. I play with a similar formation, 3-1-4-1-1 this season (coz I couldn't buy solid fullbacks) and it went surprisingly good. I used 3-3-2-1-1 to counter hard both flank attacking opponents and it went very good as well. I think it worked as a 5-4-1 diamond on defence while it had more attacking potential at offence.
btw, I don't have blue on DCs (I actually play off. trap sometimes) and I used 3 red arrows (ML,MR, AMC).

I find 3-3-2-1-1 rather solid. It turns to 5-1-2-1-1 when defending, and that's good. I also agree that your backs need red arrows.

exeis to top eleven sta ellhnika? :P