Father of the Bride / Groom

Usually yes, since it makes the group read as one party in photographs. What should differ is the jacket, typically an Argyll where the groom wears a Prince Charlie, so the groom remains the focus without the fathers looking excluded.

It works if each wears his own family sett and the rest of the party is in one neutral tartan, which reads as deliberate. What looks unplanned is several unrelated clan tartans scattered through the group with no visible logic.

Yes, and this matters more than the jacket. Agree one hose colour and one metal finish across the whole party before anyone orders. Mixed chrome and antique brass across a group is the detail that shows in every photograph.

Better not to. Tartan is woven in batches and slight shade variation between runs shows when people stand shoulder to shoulder. One order for the whole party means one cutting run and no risk of a visible mismatch.

Generally not. A fly plaid on a father can pull attention from the groom, which is the opposite of what the role calls for. Leave it to the groom at an evening reception.

He wears the wedding sett like everyone else, which is entirely normal and nobody will comment. Tartan at a wedding marks the party rather than making a claim about ancestry.