As long as it's not over something stupid and both characters are respected I don't have a problem with them coming to blows (albeit briefly). Regardless of their pasts they both have their beliefs about which direction mutantdom should go so it's natural that there's gonna be some tension. Especially now that they're engaged in activities that may require them to make tough choices. If things get tense enough (as they sometimes do between teammates) they'll duke it out briefly before someone intervenes and then they'll likely keep it moving. A good story needs interpersonal conflict and it'd be nice to see Storm have the agency to disagree with others and advocate for her ideas about what the team should do.