It's not an RPG story per-se, but it did stem from character growth.
Playing mordheim; my first warband ever, and it's still going strong. It is a reiklander (ranged-specialists) warband, and here's what I have:
Captain - BS5, WS4, S3, T3, W1: but he does better in melee than he does at range. He had two duelling pistols, never did much. Give him a jewelled sword, he carves face the first fight he gets into. Against Dark Elves, no less.
Champion - WS 6, S3, but he's got a 2H Sword, Strongman and Finishing Blow. To top it off, he's got strike to injure. That means he can hit on 3+ usually, wound most opponents on a 2+, and incapacitate them on a 4+. To top it all off, he got dinked on the head once, and now he's stupid.
Bow and Crossbow henchmen - I have four in total; all have WS 4, BS 5, Initiative 5, 2 Attacks and Strength 4, maxed out EXP. One has fallen off a 8" tall building and survived without injury. He only fell over, that's it. Another shot his buddy with the crossbow while he was in close combat.
And my Beggar. He's gone from stats of 1 or 2, all the way to being the single fastest, heavy-armor-wearing, master-mordheim-map-carrying bastard of any of my local community's warbands. He has sprint. Base movement's only 4, but he also has leap. He clubbed an Assassin into insanity, giving him frenzy. Everyone wants him dead, but three wounds and toughness 3 means people are finding it hard to put the nail in his coffin.
I am so proud of my warband.