No it wont. Vs toss, u HAVE to make tanks and maybe 4-5 marines from the start, or he will break through ur wall. If he doesn't, 3 goons will be able to shoot down that dropship before it unloads half of the marines. This is why noone drop-rushes a toss player (except boxers 2-tank drop, but it's hard to pull of)
Vs terran, a M/M/F drop will be totally wasted. He will have turrets protecting his peon line in case of a 4 goll drop, so the drop will fail. And 6 marines, 1 medic and 1 firebat can be killed by 2-3 golliaths or a single tank + repairing SCVs.
My most used tactic while Terran is in the beginning, send squads of 8 marines and 4 medics, or 6 marines 2 firebats and 4 medics. Through my experiance with this beginning tactic, it works well vs Zerg and moderate for vs Terran, however sucks incredibally vs Protoss. Stim really helps alot, since the Medics'll fix that 10hp sacrifice that it does. The medics really help the squad survive much longer. By the way, I send more than 1 or 2 at a time, just one most likely will be murdered, and only two may not sufice. Also, leaving one squad behind in the base'll help, too, in the matter that they counter.
Another strat. that I rarely use (universally) is having a squad or two a distance away from the entrance to the opponent's base, so if they attack, I can counter by rushing into their base, since most of the people I play against rarely ever keep units in thier base during an attack. Or, when they are hitting my base, I'll hit them in their rear of their attack force, while the units I have in my base'll hit them from their front side. Doesn't always work, though.