I think the TA-11 (3.5X) ACOG is perfect for the FAL. First, it has good eye relief, which is important for a 7.62x51 rifle. Second, it keeps the FAL light and handy. Third, as you said, it is not a precision rifle, but the ACOG will definitely provide enough precision while still being bomb proof. I went with the "donut" reticle variant and like it a lot.
Here is mine on a DSA FAL para carbine I sold a while ago - I still use the ACOG on my SCAR17S though:
Here is mine on a DSA FAL para carbine I sold a while ago - I still use the ACOG on my SCAR17S though: