How do you adjudicate initiating HTH?

[larsdangly]

The rules governing initiating HTH contain some ambiguities that call for table rulings, and I'm curious how others handle them.

Most importantly, initiating HTH is described both as an 'attack' (implying it occurs during the action phase of the turn) and, more clearly and in multiple places, as part of the movement phase that is resolved during movement.

An additional wrinkle is that you can enter HTH as a regular move if you are disengaged OR using a shift if you are engaged. So, two different types of moves for two different situations.

The question is, how do you handle the frequent situation where a combatant begins the turn disengaged and moves up to a foe who is large enough to engage them and tries to initiate HTH, all as part of the same move?

One interpretation would be that you are free to do so, regardless of facing and the attempt to initiate HTH happens right away, during movement on that first turn.

A second interpretation would be that you must stop as soon as you become engaged by your foe, ending your move, but you may use your action on that same turn to initiate HTH.

A third interpretation would be that you must stop as soon as you become engaged to your foe, ending your move, and you must wait till movement phase of the next turn to initiate HTH by way of a 'shift'.

This is such a universal situation that everyone has to have an interpretation; so what do you do, and why?