I don't think the existing FAQ is any more or less clear than the rules - you can still interpret it as "the formations are merged so you get to use farsight" if you want to. It does say "his action test" but it's hardly conclusive since the FAQ is on a different subject.

I think a separate FAQ is still necessary, e.g.:

Q: When a Commander issues a combined assault, can he use the special abilities and/or initiative of the other formations taking part?
A: No. The commander's formation takes an action test as normal, with the exception that the -1 modifier for having blast markers is applied if any formation taking part has blast markers. The formations are only treated as one if the action test is passed and for the duration of the assault.

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This is currently in the Master FAQ:

The Avatar activates, without the benefit of the Farsight bonus.

The BM penalty applying from any formation would be an exception, which is why it's noted in the commander rule. I think we could simply add that to the above FAQ for clarity.

Yep, and mention special abilities too?

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