I've had this idea for a week or so now, but I have never played WH40k and don't own a rulebook (though I have a feel for the general rules. Veeeeeeeeery general rules.). So, it's a list idea/format. I guess Space Marines, seems to work well 'nuff.
Flamers. Flamers and melta bombs. Each squad has 1 heavy flamer and the rest normal flamers. At least 1 melta bomb in each squad. Don't care if the squads are now 3 man teams and there's only 3 of them, whatever.
Transports for them: Rhino's, drop pods maybe, eh. You get the point. This part should actually be emphasized a lot - these squads don't have great range.
Vehicles/other stuffs: Long range, anti-tank, anti-flier. Is that a Vindicator? Maybe? I don't know? Shadowsword? Grav cannons? Attack bikes? I have no idea. It doesn't have to be long range, but preferably it is.
SO: The squads are I'd expect good against infantry, from what I've seen of flamers so far. Melta's for Dreadnoughts, Carnifex's, the like. Rhino's for getting close enough to use them. I guess you could replace the melta's with krak grenades, though I haven't much experience with melta bombs.
Other stuff is for the heavy stuff. Anything from Spartans or Rhino's to Titans. Strength D I guess. Hell, grab a Titan yourself and fit it with the heaviest antitank guns there are.
Is it stupid? Maybe? I have no fking idea. That's why I'm asking.
Heavy flamers for SM are pretty heavily restricted; only Terminators, Sternguard and the Legion Of The Damned (special unit) can get them as infantry. Furthermore, you only get one special weapon per squad, and at best a combi-weapon on the sergeant. Krak grenades come as standard with Marines, melta bombs are also only available on the sarge for tactical marines. Good news is, if you're not taking heavy weapons (none of them really gel with the mobile anti-infantry idea of flamers) you don't need to take full squads, just 5-mans, though you could take full squads with a heavy weapon and split them into two with the heavy weapon and four bolter Marines on an objective somewhere while your other half goes forward in a Razorback, which, incidentally, can take heavy flamers.
For long range stuff, attack bikes are good and mobile, Predators are reasonably well-armoured, and Devastators both regular and Centurion pack a lot of firepower into a small package.