Why didn't you say so!
That is easier to answer.
Leave credit undervalues work by 40%. They can easily recoup that under-crediting on a long haul roster but cannot catch up on a short haul roster.
If you are on a long haul fleet, then 1 to 2 weeks is ideal. Two weeks is equivalent to a long haul pattern - they will squeeze 2 more patterns out of you but that should leave you with 5-7 days off to tack onto your leave or just as a run of days off.
Short haul, or G day limited rosters, take 4 weeks if you can or 3 weeks. If you take 2 weeks they can work you 6 days straight, 1 day off, then another 4 days to satisfy the 1 in 7/ 2 in 14. So you will be working hard for the remaining 2 weeks to catch up on the hours you lost on the 2 weeks leave.
Less murkier?