First, have the option to not have attributes highlighted when you go to the shop screen. For new players it's great, but people who've been playing the game know what they want, and people with OCD like me like not having the yellow plus signs.
Second, state what armor does in the shop screen like health. I'm not sure why this isn't a designed feature already. I almost suggested putting your stats on your character somewhere, but the shop already does that. Why do I need to click my character to be able to asses what their current % reduction is?
Third, for the shop menu, allow an option to see the before and after. For newer players that are familiar with mobas, this will help a ton. The first few games you know nothing, so having an option that lets you preview the stats you'd receive from increasing something would be great.
Fourth, along with the attribute changes, allow an option to turn off upgrade suggestions. Since the game at higher level is countering your opponent's forces, sometimes you have gaps in your composition that you fill with 1 soldier unit or such. Therefore, when the game is like HEY UPGRADE ALL OF THE ONE UNITS DAMAGE AND ARMOR! it's fairly annoying.
The other issue I have is MM, but I suppose that'll be fixed when there are more experienced players. Customs or teams of 5 would be nice for those that could gather 5 people to play it, but I also assume that's another MM issue.