Don't know if I'm wise or knowledgeable but here goes. Until very recently, I lugged around 4 or 5 of the big C&F waterproof boxes for all of my trout fishing:
1. Big mayflies
2. Small mayflies & midges
3. Caddis, stones & terrestrials
4. Nymphs and emergers
I've been able to pair down my selection to 2 boxes for most fishing, although I'll probably still take everything along to unfamiliar water.