Change the amounts.
Make the soldiers not just worth one, but like an actual infantry unit
Make the Calvary Calvary that have special rules
Make the Cannon’s cannon that have special rules.
For example keep Risk’s basic rules, but make infantry if they role 1s, 2s, and 3s not high enough to land an attack
Calvary if the get 1’s or 2’s they can’t be hit
Cannons if they get 1 it won’t hit.
Also make Infantry worth 1 money or whatever they’re called in risk
This may sound retarded, but it might work.