Fellowship, just like group of heroes are hard to handle, unlike random armies, they are expensive and the problem of them is that being so few, the enemy will start targetting them 1 by 1, starting by the weakers of the group, neutralizing or tieing up the stronger ones with cannon fodder.
The fellowship problem starts with the hobbits with the exception of frodo.
If you wanted a better " fellowship" version of an army to go, I would field the white counsil instead, there all basically around the same stats and weaknesses, but also there alot more magical, proving a far more threatning army both from range/magic and close combat
Only a fellowship gets good with warriors inside, using the warriors as shieldwall and tieing up enemies while the heroes take on particular targets.