Three lane strategy card games in that genre existed for quite awhile. There was a somewhat popular series called Dixie from the 90s which did civil war battle

Three lane strategy card games in that genre existed for quite awhile. There was a somewhat popular series called Dixie from the 90s which did civil war battles using three lanes (and I assume other Tom Dalgliesh games did similar). I always assumed DotA/etc got that idea from elsewhere, but of course I have no idea.