I will be exceedingly impressed if they pull this off. RTS is probably the gaming genre that offers the most "interesting" problems in programming, and thus is the one that needs the most computing power beyond simply showing stuff on the screen.
Pathfinding is Hard. Maintaining sync is Hard. Unit AI is Hard. And keeping those performant is doubly so, especially using JS.
So yeah, I'll be impressed if they get anything playable out of this.
I think the reasoning behind using an RTS is likely that the company wants people to write inherently online games on their platform as part of whatever monetization strategy they have - and the other big alternatives are the MMO and MOBA genres, which would need a lot of content to be made. Having a couple of bright programmers on call - the designer is both a Starcraft celebrity and a mathematics nerd, so he likely can chip in too- would no doubt be cheaper than hiring enough artists/character designers or voice/motion capture actors to make a respectable game in some known hardcore online game genre...
I'm not sure I'd that path-finding and maintaining sync are hard problems, especially since they are problems that in an RTS aren't quite as sensitive to latency.
Ask anyone who's ever worked on an RTS and they'd disagree with you. It's not even difficult to find evidence to support them being tough problems by googling it:
Even without any search, you can come up with a lot of problems: Will you calculate an alternative route as soon as a route gets blocked? What if it is a friendly unit? Should it move to open way? What if it's already moving? What if it's too slow? What if there are more, moving to different locations with different speeds and priorities (For example: A tank going to help defend the base vs. a resource gathering vehicle)? What if the blocking unit is an enemy unit? Attack it or move around? Can I attack while moving? What if I can't move around? Can I crush it? Am I part of a formation? How to pass through a narrow path? Should formation alter?
As someone who has worked on an RTS, among other games, I think I am qualified to speak on the manner.
For starters, yes there are complex problems with lots of edge cases indeed. But not one of the many problems you suggest are computationally difficult. Now there are some computationally difficult problems to deal with in an RTS but those are not among them.
Additionally, a large amount of the problems you just listed are common among any game with AI. RTS pathfinding is hard, but so is pathfinding an an FPS, and then add in how much more complicated a level is in a game such as Assassin's Creed, to the more simplified structures you can manage in an RTS, and it's easy to see why this isn't simply a matter of RTS games being simply more difficult.
And within an RTS there very many problems that are much easier, both from a complexity, and computationally then in other games. Visibility determination is one thing in particular that's considered super difficult, and very performance sensitive, that's very easy to solve with the fixed perspective of an RTS.
And then there is networking, in which case you can use a lock-step model in RTS due to being less sensitive to latency, that both vastly simplifies networking. And also makes it possible to synchronize the large amount of units in an RTS with minimal bandwidth.
I think I understand. I still play AoEII only so I wouldn't know Assassin's Creed. My idea is that it would be complicated if you have massive amount of units. The calculation could be very expensive when most units are moving. As I said, that's just my idea because I'm not a game developer.
Pathfinding is Hard. Maintaining sync is Hard. Unit AI is Hard. And keeping those performant is doubly so, especially using JS.
So yeah, I'll be impressed if they get anything playable out of this.