I think doing that will cause a lot of factions to be completely countered. Part of the fun of having all these factions is having to bring fleets are prepared to face a variety of threats. If I know I'm going against Drukhari I'll just bring a ton of fast ships and long range weapons to counter their stealth, that's not going to lead to more engaging and varied battles.
We really do need a replay system at the bare minimum. The fact that there are no current plans to implement one is pretty shocking given how pretty much every decent RTS over the last 10+ years has this feature. Why make a beautiful game if you're not going to let people show it off? Even Dawn of War 3 had a replay mode and that game shipped with the barest of bare bones.
Please make this a top priority!
Unfortunately I believe the devs have stated that there are technical limits to the game that would prevent having truly massive battles. I'd love to have 3v3 and 4v4 even if it was at a lower point limit. As high as we can go the better, or better yet let people choose in custom games.
Soften them up with Nova cannons and kite them as they come into range. Use escorts to scout them so you can pick at them from range. When they get close burn away and use abilities like the stasis bubble and the lightning orb to slow them down and finish them off. I mostly play 2v2 though not so sure about 1v1.