fresus wrote:You have to be within 1" of an enemy, or within 1" of a friendly model from your unit within 1" from the enemy. So any unit can fight in two ranks, regardless of their base size.
Fighting in 3 or 4 ranks, however, is only possible for small bases.
As for the original question, we can't give you an answer. Tournament-specific rules are up to each specific tournament (by definition), so you have to check with the
TO.
Of the half dozen or so big tournaments I've been to only one enforced base size, but was weirdly only for daemons. It wasn't even an ITC but had over 100 people.