Try getting about six to eight of them. when they pair(depending on size of tank) they should pair off on their own. use alot of rock cover in your tank. Lava rock works best. I have the blue spotted gobies in tank with my tropheus illanghi are doing great. I have two pairs breeding for me all the time!!!!! I have an 120 gallon tank. These are very fun and comical fish indeed!!!!!! Big tank, no problems!!!!
I bough an unmated pair of w/c's a few years ago that paired up almost imediately. The male died after about two months (no idea why) so I bought another male and he paired up with the female straight away.