I am currently using UP by Jawbone (the
purple one), Moto Body & Google Fit. My steps right now are: 8883 (UP), 9125 (MB) and 9263 (GF). So not an exact match, but pretty close for my needs.
I installed UP because I also use MyFitnessPal and neither MB or GF will upload steps to MFP. At first UP was about half the steps of the other two until I turned on - in the UP app, under Settings>Application Preferences - the Phone Motion Sensor. I had left it off, thinking it would double count my steps - once from my watch, once from my phone - but when I turned it on my steps became more accurate.
I leave Google Fit installed because many standard apps don't offer a MB choice but GF seems to be their default. Moto Body's nice because it will check your heart rate.
As far as using Moto Body in WatchMaker Premium, you can set it to open MB upon a tap. In Customize Watch, select the icon, then scroll down to Tap Action, then Watch:Select Application. You can select MB there if you have it installed.