5 seconds to play against someone in the USA but not in Europe? That really doesn't make any sense to me. Say it's a 1v1 (for simplicity): If the servers and your opponent are in the USA and you're assuming that the latency of the two player connections is additive, then surely in that case the latency should be *lower* (or at worst, equal) compared to when you play someone in Europe? And if it's only the latency of the player furthest from the server (ie you), then it should be exactly the same experience playing against an American as playing someone in Europe.
At any rate, I've definitely never had a 5 second delay. Anything approaching one second is near unplayable, and I rarely have them despite being all the way over in Australia. However, I've been a significant proponent of the theory that battle servers make other player pings irrelevant, so your theory does have me re-evaluating that stance given that it very much is a sync-dependent game. But I'll make a separate post inviting critiques once I feel like I've properly thought it through. I'd really love to get to get my head around that whole system.
In regards to mismatching, I'm not sure there's much you can do about that. The player pool size is what it is, and I frequently get matched with top 20 players within 30 seconds of starting a 1v1 search. It would appear the system only cares if one of the players has been searching for longer than the search expansion threshold. I can't imagine it's much different for team games.
Honest to God. Playing with European people or west Asian (Russia) will yield delays of max 1 second. |Max|. On average it will be around half a second. Playing against Chinese (I have once or twice played against US and rest were Chinese or some Asian flag I couldn't discern), I have always had at least 3 second delay. That is the bare minimum that the delay will be between an issued command and the command being done (movement, ability use, ... whatever). Max it was 5 seconds the whole game. I'd record it but I really can't be bothered to. Between laboratory duties and university obligations, I can only play one game per day max and I really don't have the time to record and put up on youtube or something. I don't know the netcode COH2 has nor it's relation to the TCP-IP protocol, but it's obvious that the moment I have players far away from me, the ping will get higher.
It's strange because in other games like Survarium or CS GO or Dota 2, you can clearly see the time for the packets to arrive to Asia from my router, is around 200 ms (you can pick servers and it will show average ping on those servers). If I choose to play on Asian or US East or US West or Australian servers, the ping will be around 200-400, definitely not 3 bloody seconds like COH2 has it.
To sum up, a package going from Croatia over to Asia or US (and back again) or anywhere far will always be measured in couple of seconds in COH2 and fractions of a second in other game network infrastructures. I'd run a tracert to relic if anyone knows the server IP.