I am not in favour of adding the numpad to the core, simply because I believe there are enough members who use a numpad separately.
I actually use a Realforce 87U + a KMAC PAD myself. However, realistically, how many people do you think are likely to be interested in
just the tenkey set and also unwilling to purchase the core along with it? If I were in the same situation, I would just buy the core set and keep the alphas around, or sell them on GH. People using separate MX numpads are usually going to be pretty hard-core keyboard nerds and either happy to have some spare keys for fun or will be plugged into GH well enough to sell them easily on the classifieds.
If we compare that pretty small group of people who use a separate numpad and are also unwilling to buy the core set to go along with it with the large number of people who are likely to be confused by all the different sets for sale, I'm with CPTBadAss, stoic-lemon, and Lechner: I think having three simple and comprehensive sets actually makes the most sense.
A friend just casually posted in a subreddit thread about Star Trek our keyset the other day and I instantly got 20 people signing up on the notification list I created. Once we start promoting this widely (rather than a casual mention buried deep in a subreddit comments thread), I think we're going to bring in a lot of Trekkers who are new to mech keyboards, so I think whatever we can do to make this a friendly and welcoming set to buy for n00bs, the better.