When I've fielded all three specials, it's usually something like this:
4 MFC, HA, IF, mus, std, Dragonhide - 350pts
3 Mannies, All AHW, mus, Stubborn/Swiftstride/Scout (some combo) - 166...? don't have my book atm lol
(1-2)x4 Leadies, mus - 182 each, so 182-364pts
...Mostly because I don't have enough Maneater models atm, but also because I use them as a side harassment and not so much as a major threat. I have more models ready for them, but I haven't put the work into assembling/painting them yet

I find them all to be rather effective. I like 4-packs of Leadies, because I feel like they have enough firepower without being complete overkill; plus, I tend to roll around average for their shots usually, and they can clear out most chaff or shrink some of the T3 hordes if needed, which I find is a great use for them. The MFC are just a plain given, for their T3-shredding abilities, plus their ability to get around the field at a good pace. The Mannies are just so diverse in their tool-kit that you can make them do practically anything you want and they'll be good at it.
For the 1500pt level, you can either drop a Leadbelcher or the DHide banner from the MFC, and you can field all three of the units that I listed above. Personally though, at less than 2k, it's better just to pick two of the three and make them better, rather than spreading yourself thin on all three units.
33 Gnobs! Over 3 Packs of Trappers! Woot!
Gibblet, Nibblet, Crunchybit (from Slaughtermaster achievement)
New book WLD: 20/10/2 - Yay tourney wins and random game win!