While the CJ and YJ share similar features in suspensions there is a larger characteristic differences in motors. Just as the TJ, LJ and JK have a coil suspension, JK's have a completely different motor and transmission combination. But separating them into each individual class would create a larger band width demand in searches and file storage due to repeat questions involving axle, gearing, suspension and general motor questions.
While there is a general difference from year to year in each wrangler, over all they all share some common characteristics that many here can answer that don't own that particular year.
There are already many boards dedicated to CJ's and ones to JK owners exclusively, heck there is even a Cherokee owners group that if you don't own one you cant become a member, but separating it down to base model and or class will leave many sections lacking that 'group knowledge base' that comes from a general Wrangler, Cherokee and such that we share here.