The whole point of ambuscade was if you couldn't do the higher teir fights, you then do the lower teir ones, and if you couldn't get a party, you solo it on w/e teir your strong at.
It wasn't designed so if your absolutely new to the game that you'll achieve upper lvl 119 gear with max stats within a day or week (You can if you have a crap load of friends that can let you leech). it offers a base set so you can work your way up doing other content till your set for harder stuff, or you just persist in the entirety and grind like no tomorrow if you want the upper teir stuff but can't get the groups.
Go and read the original post about ambuscade,
http://forum.square-enix.com/ffxi/threads/50206 . on here they mention that
"Quote"
In addition, Ambuscade has a variety of difficulty levels, so everyone from seasoned veterans to those just starting out should find one that matches their needs. Those wishing to tackle the strongest foes are advised to select “Very Difficult” and be prepared for a valiant struggle!
Even if you’re not the type to try battle content at its most challenging, you’ll be able to eventually earn the rewards from Ambuscade if you keep working at it, making the content truly accessible for all.
"end quote"
If your a experienced enough player, you can chose the higher teir fights, however if your aren't, you can still attain the armor as long as your willing to grind.
Ambuscade offers something for everyone, however if you havn't put the effort in yet to have a suitable job ready for it. then you just gotta go for what your capable and grind like no tomorrow.