You need to understand that size of a plant means nothing.
A stretching plant yeilds less because it camt support the weight.
If they are autos, they yeild less just because they are autos.
Outdoor buds tend to weigh less, the buds will be less dense then a well maintaned indoor crop.
You will get a decent harvest, enough to cover the cost of what you spent on the grow.
Indoor grows are not comparable to outdoors. Its apples to oranges. LST, topping, supercropping, scrog, longer light periods, direct light, proper temps and humidity, better access to water.... These are all factors of yeild.
Also, these plants are gunma keep growing. You wont even recognize them soon.
If you wanna better yeild, you can try some of the common indoor techniques on a few of your plants to get more tops.
Either way stop crying about noone being able to estimate your yeild. Its not possible