The
most oft-quoted estimate of first weekend Apple Watch orders was 2.3 million. (With an average of 1.3 devices per order, it could be that up to 1/3 were done as double orders with the intention of returning whichever model was not liked as much. But let's go with the 2.3 million.)
Pro-Apple site
AI claimed in February that there were 6.8 million smartwatches sold just in 2014. So, using their figures, the Apple Watch sold 1/3 as many of just those. Not more than all smartwatches ever sold.
Of course, it'll also take months to deliver all those Apple Watch orders, and Apple can't count them as sales until they are.
So yes it sold very well at first. But not more than all others ever sold. Perhaps you left out some parameters, like "more than all Pebbles and Android Wear ever sold through the end of 2014." Now that would very likely be true. Pebble was a Kickstarter project and Android Wear didn't start selling until the latter part of 2014.