You end up with your other high dpsers without equivalent gear because you are too busy trying to gear a combo of 25 dps mages, rogues, and warriors some how from your progression raids?
19 mages all doing 1k dps without NF with 37% uptime on NF: 19k * 0.15 * 0.37% = 1,054 dps contributed + 500 = 1,554 vs 1k.
Hunter instead with same conditions at 44% uptime on NF: 19k * 0.15 * 0.44% = 1,254 dps contributed + 300 = 1,554 vs 1k.
Hunter and paladin at 65% uptime: 18k * 0.15 * 0.65% = 1,755 dps contributed. Paladin contributes 802 [1302] Hunter contributes 953 [1,253]
OT Warrior, Hunter, Paladin at 80% uptime: 18k * 0.15 * 0.80% = 2180 dps contributed. Paladin adds about 747 [1247] Hunter adds 888 [1188] OT warr adds 524
Then you add in the dps they are doing swinging and using abilities. Having at least 1 NF Junky is very appealing. Although, this is based on a 2ppm so numbers may vary.