I think I know their strategy, but I'll give mine. If I had done a test run I could have cut out at least a week to ten days.
I did the guitar thing like Metro, but with 2 instead of 1. All of the sims and clones got the "swimming in cash" lifetime wish. With ambitious, that's worth 40,000. Only need 5,000 more to get the voucher. If the clone did not get ambitious then I tutored him to an "a" in school then aged him up and picked it. If he did get ambitious, then I immediately aged him to teen. One of the stay-at-home sims would teach the teen how to drive for an easy 2,500 points. It was easy to get them the other 2,500 quickly - between maxed happiness bars and other wishes. As soon as they learned to drive they were aged up to young adult and given the LTW of "swimming in cash." Unfortunately, you can't use a cake twice in the same day, so there was an occasional delay. The two sims playing guitar in the subway could knock out $50,000 in a short time. The clone would go get their clone made and move out.
How I could have been faster:
- Only have one guitarist and have moved out the other one to open up a spot so I could be running 4 clones at a time instead of 3
- Buying items worth $50,000 and storing them in family inventory then selling them to grant the LTW.
- Not picking traits so the clones only had 3 traits and had to get ambitious when they were made. That or picking two traits not available to children.
- Being careful with picking my rewards. I ended up with a motive mobile instead of a clone voucher once and that slowed me down quite a bit.
- Being careful and not watching other things - I had a child clone die at his cake when it caught on fire and I didn't notice since I was watching TV, too.