I recommend trying 10
GH with 2x specials (I generally go plasma or melta), a standard and a
MoTW. I usually leave off the wolf guard on plasma squads, as to 1) get the free 2nd plasmagun and because they tend to sit back and pelt more shots in than meltaguns, so only firing the combiplasma once is frustrating- you wait for the right time to rapid fire, and you get assaulted, or you fire it range and your combi is only good for one shot (of course this is when you will roll a 1 or a 2
) If they do get into
CC the unit charging them is bound to have gotten shot up a bit, and between counter-attack, the standard, the
MotW guy and the melta squad or two that always hangs around the plasma squad, they should be right in C- at least against most things. They aren't going to stand up to
CC monsters (a block of bloodletters/genestealers, nobz, trygons etc), but unless the unit is a dedicated
CC unit the
GH don't mind getting into a punch up with them. I like to put combimelta/fist wolfguard with my melta squads, so if they fail the double melta they can charge and try and fist the vehicle. Often If a dread pods into my lines I'll try and melta it with the grey hunters, but if I say destroy a weapon or stun the dread its going to rampage into my vindicators/longfangs/etc. So that fist on the meltagun squads see's alot of action against vehicles.
Although I do have to say it's pretty hard to not do well with
GH. Either 10 men in a rhino with your choice of equipment, or 5 men in a razorback with your choice of probably less equipment since you want razor squads cheap
the last thing I want to add is think carefully about the option to buy a fist/p.weap/plasma pistol for your
GH squad. It is tempting to buy a squad sometimes with a wolf guard, a fist, power weap, plasma pistol, 2x special weapons, standard and
motw, and it does make for a hilariously tooled up troop choice, but it really isn't worth the cost. You can spend alot of points to make sure your one squad is tooled up for every situation, but as a general rule
GH are already tooled up to handle almost every situation. Dreads/walkers,
TEQ'S, monstrous creatures and land raider-esque heavy armor are pretty much the only thing they have problems with- until you give them melta/plasma guns, and fist toting wolf guard to lead them
4000
1250 
%@!&
