Sure you can! Just make own mod and then it has. Go to heroes folder\Data and there is data.pak file open it whit Winrar and seach any stats you wanna change in the game extract those xdb files and make sub folder to them and chage the stats and you have made a mod.
open mapobjects -> mpobjects -> Haven -> ( there you shall find list of heroes)
Now note that the name of heroes are differnet than the ones in the games. if you go through the files then you shall see that their true name is also written.
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