Well, realistically, 776 B.C. or whatever date you throw out is an accepted start date that lies very far back in time. It's from a time where we can't really be sure of much of anything, and our sources available to us number in the single digits. If we're lucky, there's a single good source, and it isn't even contemporary a lot of the time. Either way, the first games likely only had one discipline, it's hard to say.

Homer is supposed to have written around the same time, and we know funeral games were being held in his and similar stories (Which are similar to the Olympic Games in that they share over half of their disciplines), but we don't know much about that period. There's inscriptions attesting to what kind of games were held, who won what, and in what discipline, but realistically, not every game or discipline is known to us.

I don't even know where I'm going with this, I agree with you that strength sport should be a discipline in an Olympic in line with our modern version of it. It'd be cool to see an "Old" Olympic Games in style with the Funeral Games (Chariot Racing, Javelin, Footraces, Boxing, and Wrestling) and some other later additions in the Ancient Greek World, and then a "Modern" Olympics, featuring the Skateboarding, Bouldering/Climbing style new additions.

I don't see why you can't split them up, ya know? The Greeks did it with the female oriented games (Poor explanation), we could do it with "modern" additions and modern inventions. Anyway, ramble over.