I'm getting mixed messages across the net. In the rule book and some of the forums, it states that After Conflict Resolution, you determine if the province is broken. It states that if the attackers power is equal to or greater than the provinces defense, the province is broken. I have also only seen that a Holding adds defense to the province total.

Now on the other end of the spectrum is that some are saying that the Attacker has to beat both the Province defense, any holding defense, and the Defenders total power.

So, the question is, do you add the defenders power when trying to determine if you break the province?

What you want is the Rules Reference document.
Page 22 to be exact.
https://images-cdn.fantasyflightgames.com/filer_public/95/ea/95eab8a3-1149-4398-bcad-40a2d87be600/l5c01-online_rulesreference_v16.pdf

3.2.3. Compare skill values ¶ ↑

The conflict type indicates which skill value is used to resolve the conflict. During a military conflict use military skill. During a political conflict use political skill.

First, determine the attacking player's total skill in the conflict by adding together the skill (that matches the conflict type) of each ready attacking character and factor in all active modifiers. Then determine the defending player's total skill in the conflict by adding together the skill (that matches the conflict type) of each ready defending character and factor in all active modifiers.

The player whose side has the higher total skill wins the conflict. In order to win a conflict, a player must count a total skill of 1 or higher. In the case of a tie, the conflict is won by the attacking player. If both players count 0 skill, the conflict resolves with no winner, and the ring is returned to the pool of unclaimed rings.

3.2.4. Apply unopposed ¶ ↑

If the attacking player won the conflict and the defending player controls no participating characters (in step 3.2.3), the conflict is considered "unopposed." The defending player loses 1 honor and returns it to the general token pool.

If the defending player or no player won the conflict, nothing happens during this step.

3.2.5. Break province ¶ ↑

If the attacking player won the conflict by an amount equal to or greater than the strength of the attacked province (in step 3.2.3), the province is broken. Rotate the province 180 degrees to indicate this.

If the attacking player wins a conflict and breaks a province, he or she may immediately discard any dynasty card on that province. The card is replaced facedown from its controller's dynasty deck.

If the defending player or no player won the conflict, nothing happens during this step.

In step 3.2.3, you determine who won the conflict, and by how much.

Then in step 3.2.5, any excess gets applied to the province (including any Holding bonus).

So, to answer your question, technically Yes, but just in different steps.

Eg.
You win the conflict X strength to your opponent's Y.
If the X-Y is greater than (or equal to) the strength of Province+Holding, the province is broken.

That all makes sense now, thank you for the posts!