I should think that the reduction in numbers made reflect their sales of these figures.
I collect the Red shield variety Legionaries which are the more traditional looking ones to most people I would say.
The Ninth though a popular legion to portray because of it mysterious disappearance since there is no absolute proof of what actually did happen to the Ninth, was it destroyed in Britain or elsewhere, the shield design is conjecture given the Legions emblem and so a probability that it was something similar to what TG are using on their portrayal of the Ninth.
I remember reading that Tacitus said about two Legionaries from one side in the power struggle of 68 AD getting into the opposing armies camp at night by simply picking up shields from the opposing sides casualties because of the different legions emblem and destroying a catapult.
The twentieth Legions emblem has been found on different things that K&C use for their range and there is a high likelihood that it was the design used on their shields.
For the Auxiliaries I collect the Blue shield variety, whether the Red are more popular I couldn't say and no doubt time will tell at present I don't think many collectors collect auxiliaries at present, though it was them who usually bore the brunt of initial fighting. The Legionaries with all their various skills being a too important commodity to use indiscriminately.
Steve