OK, I have had my encounter last night. (As a side note I also won

)
I was a bit cautious so only used one BG of MF bow and had 4 other BGs of bow in LF formation. My MF was a BG of 8. Had them stuck in between two defensive spear BGs and anchored by noble cavalry on either end with more LH skirmishers.
The MF went up against a BG of legionaires, which went fragmented and decided against moving forward any more. The other BGs I went against were two Roman MF bow in BG's of 4 each. They were protected against my unprotected MF. This is where the dice roll saved me a little and I also CMT'd to expand the MF so I could get more dice shooting. One MF went routed and then I became bold and CMt'd to charge the remaining MF bow. Not a good idea. Dice rolls were not that good and in melee he had a + for the better armour. he joined a general there after they went disrupted and brought them back up. My dice rolls were poor so it became a quagmire.
Lesson learned, never charge your MF bow, even if the opposition is MF bow. Just shoot it out. MF bow with LH or LF bow support will just annihilate anything. I played against Romans and what won it for me was the shooting I did overall. Two legions, one spear, two LF and two LH routed just from shooting.
Thanks for all the tactical tips and now I am pleased that MF bow can be usefull to your list, even if they are unprotected.