The research system definitely could use some tweaks changes and new research, but I'm not a fan of research carrying over to a new race after switching. As someone said previously it's going to create cookie cutter armies, everyone will have gold spiders for instance. It's going to be a large advantage for the biggest players (mind I'm the largest power on my server), we will be able to stock up honor and resources switch races build the best units for each rare resource and have a powerful mixed army, and unbeatable garrisons. The mechanic of getting a mixed army currently is done through having an active house that trades units for large fights. Think this is dampen team work first of all, which is a large part of what is game is suppose to be about. Also this will strengthen already hard to, or near impossible to attack castles. Again stock pile resources switch races make monster nasty garrisons. IMO getting to be able to make mixed garrisons and armies should require a lot of time, work and resources. You should have to start over on the new race, not play which race suits your current game status. As I see it people will start human build a garrison of archers, then switch to lich for scorpions and spider pvp plus spider garrison. Switch to dwarf now and then for mechs and tanks (easy diamonds for big players on servers, I'll have endless supply of tanks). Garrisons will be a huge problem, castles will be much harder to attack. Also the new feature recently added of seeing a persons castle when clicking them, to know their race before a battle is useless now, thinking you know a garrison based on race is useless now. Ohhhh not to mention on raiding castle issue, some races can't use a rare resource efficiently and have extra raidable of that type, this will also go away.
I think a better, different fix/change would be to make research carry over when switching races. Maybe not 100%, or a new research to make a % carry over, or a building you could build each lvl carries over a % etc etc.... how does the fact I researched gold spiders at all make sense that if I switch races I know understand how to build gold tanks? The mechanic not only hugely game impacting also doesn't make logical sense. Not sure all the ways this will impact the game have been thought through! Switching to a race early in the game and sticking with it research should be a comitement and rewarding not easlily flexible. This is not a fix for server status, it will not make people abandon less accounts and keep servers fuller, which I think is part of the idea here.