if dorsius gives regenerate 2, the answer is NO. Regenerate X and Regenerate X does not equal Regenerate 2X. Traits that have "+X" will stack. For example melee +2 and melee +1 does equal Melee +3.
If Dorsius says heal 2, or remove 2 damage than yes, Regenerate 2 and a different healing effect can work together
Dorseus, Stallion of Westlock
14 mana, level 4 holy, Animal, Horse
2 armor, 11 life, 4-dice quick attack
Aegis 1, Legendary, Regenerate 2
During the Upkeep Phase, Dorseus may heal another friendly living creature in this zone 2 damage. This bypasses the Finite Life trait.