PLEASE LOOK!! Need EVERYONES OPINION!Would this be okay for multiple plants? (Picture included)

I know you're typically not supposed to share planters with more than one plant, however, would this be okay? I was planning on planting 2 or 3 femanized auto northern lights, from nirvanaseeds.com. I am usuing fox farm soil with some coco perlite mix. How much roughly would they yield. Outdoors in az oh and by the way the pot is 2 feet long, 12 inches wide and 10 inches deep. If so, should I do 2 or 3 plants and how much do u think they yeild? THANK YOU please give me answers whether they're pro or cons or whatever I wanna hear what everyone's opinions and thoughts are about it. I am trying to learn as much as possible. Thanks again

Depends on how big you wanna let them get. If your planning on growing 3 small plants then by all means that'll be fine!

Plants should have their own root zone to grow in, if you insist on using one planter for multiple plants...
... you should insert something to separate the areas, like a piece of plastic (cut a lid), a styrofoam plate cut into shape, or even a piece of cardboard at last resort.

I was planning on planting 2 or 3 femanized auto northern lights, from nirvanaseeds.com. I am usuing fox farm soil with some coco perlite mix. How much roughly would they yield. Outdoors in az oh and by the way the pot is 2 feet long, 12 inches wide and 10 inches deep. Should i so 2 or 3 plants and how much do u think they would yeild? In arizona

Since no one else is chiming in, I will suggest 2 plants in that container.
you can go 3 if you only want to veg for 2 weeks, but if you want to go 3 or 4 I would opt for 2 plants, with the divider.
Yield will depend on the strain, and the size of the plant (veg time), and the lighting you are using. There is no way to say for sure what you can expect, without knowing these variables.