Older leaf spring Jeeps got along fine without their antiswaybars but not the coil spring TJ. Leaf springs are pretty stable laterally but coil springs are not stable in any direction so an antiswaybar is key to keeping the axles under control... especially in the rear. On an extremely steep or off-camber trail, the presence of an antiswaybar could make the difference in rolling or tipping over and not rolling or tipping over.
Even John Currie was running front and rear antiswaybars in his TJ when he won the overall U.S. national (ARCA) rockcrawling championship several years ago.
Edit: Some very basic stripped down models of TJs did come without a rear antiswaybar in early years but my '97 came with one and I think all later models all included f/r antiswaybars.
Dropped Pitman arms are only installed in TJs in rare instances like on extremely tall (like 6") suspension lifts or when the upper end of the trackbar has been dropped down via a dropped upper trackbar mount. For typical lifts, a dropped Pitman arm should only be installed if there is a corresponding drop at the upper end of the trackbar which is a pretty rare thing to install. Pretty much all CJs and YJs needed dropped Pitman arms once a suspension lift was installed but they had a different geometry steering system which needed it.