Debates, arguments, and fights with your cofounder are absolutely fine if you both equally care about the business. It usually means you both want the best outcome.
Where it becomes different is when one person cares more about the business than the other. Those aren't really strategy fights anymore, they're commitment issues.
The most important distinction is figuring out which camp you're in. If you both care equally, compromise and move forward because at the end of the day you're both trying to build a successful company. If one person is consistently carrying more of the weight, that's the problem you need to solve first.