2 apple watches with 2 iphones in one apple ID

I know if I have 2 watches and pair them to the same iPhone, the iPhone will automatically “pick” the watch i’m currently wearing and sync the activity data….

my scenario is that I have 2 iPhones (signed in the same AppleID), now I want to pair each iPhone a watch, and wear different watch for different activities (e.g one for swimming, the other for mountain climbing). In this case, paired to different iPhones, will the activity record sync and merge together across my iPhones? (under the same AppleID with everything switched on)