That’s great. My preferred Cortex Prime build is also MHR and swapping Affiliations for Relationships and Values.
Mine's Firefly...
Distinctions (which also grant skill levels and must include a role distinction) (D4 or d8 by use) and carry 3 SFX, of which one is open at CGen.
Attributes (Physical/Mental/Social) - which is a bit too few - but if we make it (Physique/Agility/Intellect/Social) that feels better for more general use to me. (ratings d6 to d10)
Skills ×19, ratings d4 (unskilled) to d12 - total 18 steps up from d4's (3 from each of 3 distinctions, 9 fro player open choice)
Specializations (either present at d6 or absent)
Signature Assets (which carry some SFX and can be d6 or d8 rated, and are very limited)
Specializations and Signature assets come from a single pool
Assets (d6, no SFX)
That also sets the scopes, almost.
If the scope is ship, the attribute used is from the ship, not the PC. (Must, not can)
The ship's distinctions can be used in place of the PCs. (Can, not Must)
The Scene has it's own scope layer, as does any significant item not tied to a player
Complications are another scope layer.
So, total scope, no SFX nor PP spend:
1 × distinction, 1× Attribute, 1×skill, 0-1 = specialty, 0-1 signature asset or asset, 0-1 scene asset/complication, 0-1 target complication, 0-1 scene distinction (if there is one, it's advised to be rare).
3-8 dice before SFX and PP spends.
SFX can often increase the number of dice.
PP can directly add additional of any given scope.
It's implied that a whole adventure could also have a distinction and/or asset/complication.
Expansions add Reputation and Big Damned Hero dice as separate scopes, as well.
Choosing your scope for what can be in the pool really is comparable to the Bounded Accuracy of D&D 5 A larger scope does mean higher rolls, and more ties, too, if equal. It's also important to note that if both sides have equal small dice, it's more likely to be a tie as well. Equal dice in the upper end (d10/d12) generally tend to not be ties as often...