This comment stands on any double medic + other class combo IMHO. I've been rolled by enough double uber soldiers, demos etc. Beau has a point, it's the medic protection and the medic ability to deliver the uber. Enough people make the same mistake! Don't ignore the medic....

I don't think anybody ignores the Medic, John. The Medic is probably the easiest to kill considering his lack of self-defense. The reason Heavy/Medic combos are so effective is because of the Heavy's ability to protect his Medic from close range threats (such as Scouts, Pyros) whilst Soldiers and Demos offer little in terms of protection by comparison. With no protection, how can a Medic build an uber safely?
All it takes is a decent sniper or spy on the other team to make playing Heavy hell.
Snipers have to be scoped in, completely vulnerable to Spies, Scouts, Pyros, etc, to get a fully charged headshot to take down a Heavy. Not only that, but one could argue a Heavy shooting at the Sniper was medium range is enough to put off his shot. I know a few Snipers that can take that sort of mechanic into consideration when they take a shot but nobody on the WDG pub is JH are they?
Spies have to get in position and wait. Although I'm not a good Spy by any stretch of the imagination, one would assume they would get after the easier kill over killing a Heavy. Secondly, Heavies tend to stand near Sentry nests -- especially on A/D type games -- a majority of the time and only play aggressively when his Medic has an Uber.
I cant believe i am saying this but i agree with junta. find solutions not restrictions.
Then why was it last year after the Engineer update the Engineer limit was reduced down to 2? One could argue On that note, why have class limits on in the first place if we don't want restrictions?
My argument still remains the same, which has yet to be rebutted:
- A Heavy/Medic combo can roam around the map happily, traveling as fast as the Medic (GRU), and still offer instant protection for his Medic at mid/close range (Minigun) and even keep the perp in sight whilst they try and retreat (Natascha) but don't worry too much about ammo because your primary weapon doesn't need reloading!

What's wrong? Oh, did your Medic get injured and there isn't a health kit for miles? Don't worry, because Heavies can also act as a traveling health kit for your Medic (Sandvich), it'll regenerate in 30 seconds time so don't worry about losing it forever.

- By comparison a Soldier/Medic combo can still roam around the map well (via RJ'ing) and the Soldier can protect his Medic quite well with his rocket launcher, he can even juggle the perp away, perfect! Until his magazine runs out of rockets and then he's left to fend off anything with a shotgun or wait until he reloads a rocket or two -- if the pocket picks the latter route then his medic is left out in the open to die. Oh, and to top it all off, the Soldier has a weapon which blocks healing.

As a sidenote, even though one can argue the shear damage power of the Demo/Medic combo, using pipes effectively takes time and even then they're difficult to connect with opponents, especially Scouts.

Sadly, Soldiers and Demos don't have a means individually to heal their Medics without the need for a health kit.