Gipsy,
One can always lead with power.....when the decision is made to go around you invariably want to fly up....adjust collective to climb power....adjust the pitch attitude either by means of the GA Button or as you suggest....manually using force trim on and ATT Mode.
After you are established in a climb....the rest of procedure can be dealt with.
A note....the canned Missed Approach is fine if that is the same as the clearance you were provided as there can be non-standard instructions given.
Now some Sky God shall come along and want to argue which action should be "first"....but either pitch or collective is fine...but for sure the collective must be adjusted to climb power or all the other actions will not matter much.
It worked in the Huey with no SAS or AFCS....and every other dinosaur aircraft.