I am a strong advocate of new shooters starting pistol training with irons. Once they're able to present with their sight aligned 99/100 times, consistently run a Bill and Failure/Mozambique under 4 seconds (all hits in alpha), B8 with 90+ points, start training with an optic. At that point they'll likely have their stance and grip in a solid place.
Then, training with an optic will force further improvement on fundamentals, especially grip and all the things necessary to better
control manage recoil. Then it's working to get those drills in under 2 seconds and 95+, respectively.
Here is
JJ Raccaza, former US Air Marshall, USPSA/IPSC Grand Master and world champion, debunking the myth irons are better at CCW distances:
Here is
Isaac Lockwood running
1.20s Bill Drill with an optic: