The New CAS Story Mode

I must say I was excited about this story feature however I like to create my sims using genetics. Eg - I pick a random guy and girl sim and combine their genetics to create a new sim. Their features tend to be more unique that way. I was disappointed to find I'm not able to create a sim like this first and then add the story mode onto that sim. I think it is too restrictive to force us to create the story before creating the sim. I think both options should be available depending how you prefer to play.