Is Sam Wilson's Ld Compulsory?

[Jonah]

Sam Wilson's Ld states 'when this character or an allied character is Dazed or KO'd, choose another non-Dazed allied character.  The chosen character removes 1 wound, removes one special condition, and may advance S.  A character can be affected by this leadership only once per round'.  In the following scenario what happens:

There are 3 characters.  Character 1 has already been affected by the Ld when character 2 is Dazed - do you have to choose character 3 to be the recipient of the Ld?  Or if you don't move/heal etc. do you count as not being affected?  

This matters because in the case of Field Dressing, character 3 may get another opportunity to use the Ld which they would be ineligible for if they had already been chosen because it is a must.

[Thoras]

Yes, if there is an eligible character available, you will have to choose a character.

[Jonah]

For further clarity, if you choose a model (to continue this example character 3) but don't move/heal/remove a condition do they still count as chosen for the purposes of the once per round limitation of the Leadership? Thanks.

[Thoras]

2 hours ago, Jonah said:

For further clarity, if you choose a model (to continue this example character 3) but don't move/heal/remove a condition do they still count as chosen for the purposes of the once per round limitation of the Leadership? Thanks.

They do, yes.