I'm going with the ambiguity of the wording on Dutch's card. If his card had said,"The chosen ship may immediately focus." Does that mean it's taking the focus action? Or does that mean it's granted a focus token? There is a difference there which gets to the heart of the matter of the question at hand.
Night Beast's card specifically says "may take a free focus action", and Garven's card says "may place that token". But Dutch's card doesn't say "May perform a free Acquire a Target Lock action" or "may place Target Lock tokens".
So how do you acquire a target lock? I think you do so by performing the action as listed on page 9, which DSA prevents. If you're saying, "I can acquire a target lock without performing the acquire a target lock action,", then Dutch's card should have been worded to say something like "the chosen ship may be assigned target lock tokens" or some such. It isn't worded to say either of those things, hence there is ambiguity there. And the debate lies in the interpretation of Dutch's card. I've always understood it to mean you are performing the action. But you might say you're just getting the tokens without actually taking the action.
And the R5 FAQ is in response to the question asking if it violates the taking the same action twice in a round rule. In which case, you have already taken the Acquire a Target Lock action, and are maintaining it on the same ship instead of taking the same action twice. The DSA card prevents you from taking the action in the first place.
But, I agree that there is grounds for a clarification from FFG.