At some point I'm not talking theoretically. I have playing Tom with raise the shire in 4 different decks with something like 10 games each. That how I see that, no matter how farmer maggot is theoretically stronger (I was initially thinking he was as strong as Bilbo before seeing him as a second-range target), we often prefer smaller allies, because farmer is overkill on the turn so we prefer enjoy some effects, and be able to play the hobbit the next turn.
You absolutely must play distinct hobbit allies. If you want to also play multiple farmer maggot (I think 3 is nonsense since you will almost never get 2 in hand/discard pile when you want the third) it have to be in addition. I understand this, I often play 2 Bilbo for the same reason.
Here is some decklist illustrating how I build those hobbit deck:
http://ringsdb.com/fellowship/view/4494
http://ringsdb.com/fellowship/view/4495
http://ringsdb.com/fellowship/view/4500
http://ringsdb.com/fellowship/view/4501