I recall that Supreme Commander used the same technique, a fully deterministic sim run in lockstep by all multiplayer peers. For it's era, it had very very high scale for an RTS game. (thousands of units and enormous game maps (the biggest of which took 15+ mins to send naval units across)
If I recall correctly, there was another benefit. You could save a multiplayer game by just having all peers dump the current game state to disk and resume it later. Since a big SupCom game could take HOURS this was a great feature.
However, there were 2 issues with SupCom's implementation.
1. It wasn't perfect and sometime hours deep into a big game, you would get a "desync" error and it was unrecoverable.
2. Everyone needed to be able to run the sim at the same speed. So the game could only progress at the speed of the slowest player's computer. And SupCom was VERY compute intensive.
> For it's era, it had very very high scale for an RTS game
> So the game could only progress at the speed of the slowest player's computer. And SupCom was VERY compute intensive.
It might surprise you to learn that these statements are still true! SupCom:FA (still playable by buying a copy and through the third party FAF launcher; they have even fixed most of the desyncs, it's very stable these days) is probably still the largest scale RTS out there (even planetary annihilation only feels larger). And it still requires a top-tier gaming rig to play.
The reason for this is pretty straightforward, CPUs actually haven't gotten faster for well programmed, cache aware, tight-looped CPU bound operations in the last 15 years. And in fact there are arguments for why something like SupCom:FA would be difficult to make today given the industry's reliance on game engines. And games are still rarely threaded more than SupCom was (e.g. game logic thread, render thread), so until someone can get back to the low level excellence of SupCom:FA and then design and implement a concurrent game logic loop for it that actually parallelizes well, I think it will remain the king of high scale RTS for quite a while.
If I recall correctly, there was another benefit. You could save a multiplayer game by just having all peers dump the current game state to disk and resume it later. Since a big SupCom game could take HOURS this was a great feature.
However, there were 2 issues with SupCom's implementation.
1. It wasn't perfect and sometime hours deep into a big game, you would get a "desync" error and it was unrecoverable.
2. Everyone needed to be able to run the sim at the same speed. So the game could only progress at the speed of the slowest player's computer. And SupCom was VERY compute intensive.