Just cause the rods lighter doesn't mean you have to go lighter with the leader. Ladyfish are a blast! Like mini tarpon!
Actually I used an 8# tippet on my 7 and 9wts as well......and yes the ladys are fun and would be even more fun on the 5wt.
...I use 6# tippet for most of my freshwater warmwater fishing except in real heavy cover. 6 and 8# will take a lot of pressure unless it is nicked. Just my experiance so I seldom feel the need for heavier.