People with the same goals, alignment, or personality are more likely to mesh well together. Even if they were your enemies yesterday, you find it easier to befriend and work with them. Yesterday's enemies can be today's friends, against a common foe the both of you somehow work wonderfully together.
It's easier for people to set aside their differences and work together. You'll be more likely to work well together on a team. This even makes actions like Tinkering together easier.