best way to sync daily activity, oura, garmin or fitbit air?

So for a while, I have set my daily activity to zero and using a tracker to monitor my daily calorie from activity. I am mainly using my garmin epix pro gen 2, which also can track my exercises that I set up.
So I get the interesting feed in cronometer that breaks up my activity into active and rest, so the calorie counts are mixed between the daily activity entry from garmin and then extra calorie burn from any exercises I log.
This has worked pretty well.
I was curious to trya fitbit air, but that would require I guess turning off garmin and using health connect to sync activity to cronometer. And then logging exercises might be tricky, I guess I could turn off garmin in cronometer and only import activity from health connect. But does that sound like I would set it up correctly?

And if so, uh, how accurate do we think those calorie counts from a 24/7 wearable are compared to just setting a standard daily activity and add in exercise?

And I have an oura ring to track sleep...which...the fitbit air probably might replace....eventually. Sigh.