Different perk "branches". Ie Tank, Anti Crit, Dodger, Burst, Sniper, HtH, Sneak, Medic with around 4 levels each.
For example, the Sniper Branch would be
1 - More Crits
2 - Even More Crits
3 - Sharpshooter
4 - Better Crits
4 Perks per branch type, roughly.
So you'd have 8 Branches, with 4 each for a total of 32 (ish) ... then with other perks that don't fit into this structure (Pyromaniac, Bonus Moves, etc)
You'd still have the same number of combat perks as you do now, 7 normal and 5 with skilled, just more options to choose from.