The MLB playoffs have weird matchups

For example, look at the royals and astros series. The astros have been in the national league for years and the royals have been bad for decades so the only way these teams could meet in the post season was in the post season which was highly unlikely. Yet here they are in the 1st round. It's the same with the blue jays and rangers. Both of these teams have been bad for lots of seasons in the 90's and 00's but this time things worked out well and both of them won their division