I am not a purist when it comes to having fun with the scale miniature world. I do have a fussy - historical, mischievous, evil twin on my left shoulder, but my angelic right shoulder self with a slightly tilted halo is generally in control of my miniature world. I have a collection of odd little hotwheel type die cast cars that tend to show up in my here and now miniature world, should I actually finish s-o-m-e-t-h-i-n-g in this decade. (Does the decade end in 2020 or begin in 2020? Good grief, I hope it ends in 2020, or I'm in trouble.) I attended Guild School Classes in 2014-2016 and Guild Study Program classes and is ANYTHING Finished???
The miniature world does not have to be perfectly scaled, especially when it comes to a painting.
I've been to a lot of museums and there are some huge paintings in the art world. If you actually painted a miniature of Monet's waterlilies and put it on a table to offer it for sale at a true 1/12th scale, had I not seen it in real life in Pittsburgh, PA , I would have initially thought that miniature is waaayyyy too big... so it needs to fit in an appropriate miniature setting. Large paintings or small paintings, even when I read about the size of the painting in a book, I am always amazed when I see the original work of art, in person.
Miniatures as Art resides in the soul of their creators. We, the collectors and We, the artists in the miniature universe have to be open to the Art within us... with painting miniatures, you really do have the best position, you can create at the size you wish and as long as it looks right to the artisan, you have met the criteria of the "Golden Rule", which is simply, its ok to do the math, but trust your own eyes!