(5E) Easier way to generate random characters?

I have a game in which my players constantly face against randomly-generated wizards. Every choice you have when creating a wizard is taken at random and they face waves of these wizards in PvP fashion. If they win, they can recruit these wizards and use them for the next wave. I manually create character sheets for these randomly generated wizards before each game and was wondering if there is an easier way of doing so since it's extremely cumbersome. Any automation of the process would be great. Writing down every single spell every single time is proving to be a test of my patience.

Do these wizards all have the same stats, and just different spell lists? What is different/randomized between the wizards? Do they have different abilities/attacks? Since you have a Roll20 Pro subscription, you could use ChatSetAttr to adjust attributes and repeating elements (such as spells) on a character sheet.   If the wizards are all the same except for their spell lists, then you could just have a default NPC wizard that has all of the possible spells and use the prepared/not prepared toggle to show which spells that wizard has. Then you would just duplicate the wizard with whichever spells are prepared. It would also be possible to use a script to delete any spells that are not 'prepared'. I'm not sure how easily Metascripts or Scriptcards or some other already written script could do that, or if it would be easier to write a custom script for that.  It is also possible to use a script such as ChatSetAttr to populate a character sheet from scratch, but it would take a lot of prior prep work to set it all up in something like an Excel spreadsheet.