These are quick drafts, so they arn’t nearly perfect...

 •Frodo burdened companion  
companion hobbit
strength 3
vitality   4
resistance 10 ring bearer
Every time a Nazgul is played wound that nazgul.  
Exert frodo for each burden added during the shadow phase.
 make it you may wound that nazgul. otheriwse an interesting card

 •Sam Frodo’s guard  
companion hobbit
strength 4
vitality   4
resistance 6 ring bearer
Sam is strength +1 for each artifact and possession frodo bears.
Regroup: Exert sam to remove a burden.
If Frodo dies make sam the ring bearer.
 remove the regroup ability and you have a good card maybe lower Sam’s resistance to 5. 

 •Merry Brandybuck 
companion hobbit
strength 3
vitality    4
resistance 8
Skirmish: WHile at a river site, exert Merry to make a hobbit companion strength +2.
If you can spot pippin, Merry cannot be overwhelmed.
 second ability is overpowered. make it "cannot be overwhelmed unless his strength is tripled".

 •Pippin friend of Merry 
companion hobbit
strength 3
vitality   4
resistance 8
Skirmish: exert Pippin to make merry strength +2.
Regroup: exert merry to heal pippin.
 fine by me.

 •Gandalf, Frodo’s adviser 
companion wizard
strength  9
vitality    4
resistance 8
Every hobbit companion is resistance +1.
Fellowship:  Exert Gandalf and spot sam to remove a burden.
make it Each hobbit companion. otherwise looks good. except 9 strenght might be a bit much

 •Aragorn great tracker 
companion man
strength 8
vitality   4
resistance 8
ranger hunter 1
Skirmish: exert Aragorn to wound a minion once. (or twice if that minion is a hunter minion.)
Regroup: spot a minion with two or less vitality, and exert aragorn to discard that minion.
 great sounds bad how about Experienced Tracked. The regroup ability is to strong in my opinion maybe make it something to do with sites.

 •Gimli great warrior 
companion dwarf
strength 7
vitality    3
resistance 7
damage +1 hunter 1
Gimli is strength +1 for each hunter minion you can spot.
skirmish: exert Gimli to wound a 

 or 

 minion.
 fine by me.    

 •Legolas elven archer 
companion elf
strength 6
vitality   3
resistance 6
archer 
exert Legolas twice to make each the fellowship archery total +1 for each hunter minion you can spot.
 I am getting a serious sense of deja vu.  Legolas, of the Woodland Realm anyone?

 •Boromir Loyal lord 
companion man
strength 7
vitality   3
resistance 7
Boromir is strength +2 while you can spot Aragorn.
skirmish: Wound Boromir to wound an 

 minion twice.