How many teams before you consider it bizarre? As a mere individual contributor / senior dev, I've only ever officially been assigned to a single team at once, but there are times when I'm juggling tickets on 3 different teams' Jira boards and attending 3 different standup meetings. Thankfully, I typically don't have to worry about sitting in on more than 2 teams at once, and I'm definitely an outlier. For me, this arose from joining a growing team before it split several times and also from predating all the current product owners.