Well, since I've only been playing the game for less than a month, I may not entirely know what I'm talking about, but I had similar problems early.
I own 8 gremlins, 4 piglets and 4 skeeters, and almost never field all of any of them.
Let's run down the issues:
1) Gremlins die too easy. Cover, LoS, Defensive Stance and giving the opponent more critical targets to attack will help this. Also, if Gremlins die, more important things aren't dying, and everything else is more important.
2) Som'er Teeth-seeking missles. ST usually doesn't move my first turn as he is casting Get Yur Bro and/or healing Skeeters. Warpig should frighten any master because 3 attacks at 3/5/7 Dam with a +flip on the Dam will give any model pause. Skeeters can damage and/or tie up stuff at range.
3) really tough models--keep the warpig alive and he can kill an entire opposing force, use your numbers to overwhelm when possible (Stampeding piglet + 2 skeeters can clear out a cluster of any force)
Strengths of the Bayou Gang:
a) numbers--you will start with maybe twice the activations as your opponent, so you can always out-wait your opponent.
Pull My Finger--auto-damage burst spell that can ignore some of your own troops.
c) Stampede--Stampeding pigs should be feared by your opponent, and if he doesn't, you need to teach him
d) lots of healing--there are alot of ways this army can heal itself
e) speed--only Skeeters can't go Reckless, Skeeters fly, pigs can be pushed all around the board 10" at a time
f) fun--since I grew up in a place with an accent, I can lay it on thick; lots of flavor in the abilities/actions/spells names, etc.
g) summoning all over the place
h) Som'er Teeth can empty your opponent's hand with no opposed flip