I was lucky to be sold several sets of the Revell TYW collection at a very nominal price about 4 years ago. These form the basis of my Renaissance wargaming armies.
The ACTA ECW figures are a useful addition as is the Mars figures. One of my Covenanter Horse units is Mars with Tumbling Dice heads....fits in perfectly.
Metals are Tumbling Dice with a few Hinton Hunt, Warrior & others.
My small Parliamentarian army is all plastic, as is half my larger Royalist force. My Covenanters are all metal & I think they match the plastics well. Indeed, I have a Covenanter Dragoon unit with 5 figures per base. All but one figure are TD. The extra figure is ACTA (with a TD head) & I challenge anyone to pick it.