Using a Forerunner 15 & Fitbit

I have been using a Fitbit to track my steps for a few months now. I really enjoy using it, it's motivational, it syncs great with MyFitnessPal and now that I'm used to it I would prefer to keep using it.

My husband just purchased me the Garmin Forerunner 15. I was looking for a heart rate monitor and ended up choosing this one because it also had GPS functionality.. I wanted mainly to use its GPS function when we bike ride. Sometimes we do road rides but we also ride trails and I feel much safer using the watch as my GPS as opposed to my phone. And maybe someday I will take up running again and it will be useful for that too.

I didn't realize this when we purchased it but the forerunner also tracks steps. This was not a function I was looking for or even really want from the watch. I only wear the watch during workouts where I want to track my heart rate and bike rides. I do not want the steps that my watch counts to override the steps from my Fitbit. I want to wear my Fitbit all day, and the watch only when I need to. Plus I don't especially trust the step counter on the watch as it is worn on the wrist. I also do not especially want to wear the watch all day.

Does anyone use those both or either one of these tools and maybe have some insight on the best way to go about tracking activities so that I'm not doubling up on things? Is there a way to disable step counting on the Garmin? When I sync my steps with my Fitbit onto MyFitnessPal will Garmin override my steps? Will Fitbit sync to Garmin... and so on. Lots of questions, just throwing them all out there. I have been scouring the boards and the internet trying to see if anyone is in my same position and I really haven't had any luck. Thanks in advance!