TRS80, other than model 1

I always wonder what the rational was on the "6000" name. I understand Tandy wanted to move away from the "TRS-80? name, hence the "Tandy 6000?, but it was really just a slightly enhanced TRS-80 Model 16B. Now, the ?16? name makes sense?16-bit OS support on the added cards. Of course. at the same time, Tandy had the x86 series with the 1000, 2000. etc. Giving the machine a name of 6000 makes it seem like it was supposed to be their top-of-the-line machine. Now many (including me) would argue that it actually was their top-of-the-line machine since it ran multi-user Xenix. However, I?ve read that at that point that Tandy had little interest in continuing the Z80 lineage Model II line so why would they give it a name with such prominence above all of their new x86 lines?