I was thinking of making a party that consists of mostly rangers that can play off each other. 1 Man gets orcs, bugbear, etc. while the others get different races. 1 Man is a full ranger, 1 man is a rogue/ranger and the 3rd is a barbarian or fighter ranger. The full ranger has the most spells which help greatly, the rogue ranger is the sneakster and still fights, and the 3rd is the most combat oriented.

This seems like a good idea, does anyone think something like this would work?

As long as you have a pure cleric and a pure sorcerer or (specialist) wizard any party of 6 will be able to beat the game without too much trouble, even with your 3 rangers.

It's possible to beat the game with only your 3 rangers, but definitely not recommended.