for a set camp or short hike and camp, I agree with three blades but not sure the "heavy" needs to be a knife. I use a 14" Fiskars axe in the pack for that. a Fallkniven A1 on the belt as my "do all" medium but an ESEE -4 or -6 would be a good choice as well. I also usually have a multitool with a small wood saw on it.

for backpacking I see the logic of using a two knife system to keep weight down. I use a 7.5" Scrapyard and the aforementioned Mora in this case.

for day hiking I'm happy with only the Fallkniven A1.

now, regardless of whatever other blades I choose, I also keep a couple Exacto blades and a handle in my medkit.