There is a related thread here 7 days during first year or 14 days during first two years?
The issue is the regulations are unchanged since the cards were 1 yr (1st card) 2 yrs (subsequent cards) so they say
year 1: 7 days
year 2&3: 14 days
year 4&5: 14 days
year 6&7: 14 days etc.
But your 3 year card covers years 3&4&5, so it your lawyers’ advice is presumably first to satisfy the year 3 requirement by spending 7 days (2nd half of years 2&3 requirement) and then satisfy the year 4&5 requirement by spending 14 days during those 2 years.
Nobody knows if AIMA actually cares to enforce these outdated regulations, or if just doing the right total days during the card validity (e.g. 21 days for a 3 year card) is what matters.