Haven't tested, but i'd imagine it would be hard to incorporate all three because of very different base damage scaling.
If you wan't three damage sources, maybe go with frontloaded damage, and 2 dots, scaling generic damage.
Just a few ideas:
Bleed poison with fat phys base, or burn poison with fat fire base and % elemental added as chaos damage from items or i.e. trickster passive.
I'd maybe go with scaling minion damage with new Spiritual Aid passive, because it's generic damage, so would apply to frontload and all types of dots.
Also look out for items that give generic damage i.e.:
new staff Grey Spire gives up to 300% generic damage,
Cyclopean Coil also gives generic damage, etc