The current series of DWTS has seen two pros being 'promoted' from the dance troupe. One went out very early (I think 1st), the other has proved to be very popular. So the dance troupe can audition new pros, as well as resting old pros until suitable partners roll around. But then again, DWTS has always had a more fluid relationship with its pros. There are some who are on it every season, there are others who are seemingly invited back as and when someone requests them or they are particularly suited in temperament/height etc. Louis, for example, returns to do pro dances with Karina, and occasionally partner a particularly short contestant. It is for me, one of the best things about DWTS, and something they beat SCD with.
So while I would love to see Ian say, because they had someone tall (just imagine how Holly could really straighten up with him or Matthew!), it's not going to happen because SCD doesn't work that way. It seems that once you're in, and accepted, you're in. Until they get rid of you, but when that happens, you won't come back. But that does give us some great new dancers, and sometimes some less than great.
Pasha has been a wonderful addition this year for me. Artem was fabulous with Kara last year. Robin may not be as strong, but has forged two good partnerships with less confident celebs. Natalie has been great with talented partners and this year is really getting the best out of Audley. Part of the reason they've been as good as they are is because they bring a fresh approach to their dances. Just imagine if a few of the current crop were rested, what great new pros we could get?