since the meyer is a hybrid (cross between lemon and mandarin or orange) the seeds will not be true and why you see the different growth. plants from seeds can take a couple of years before they flower.

Here is an image of my babies. Is there any sort of regular maintained in should be doing for these since I am keeping them potted?

I would not trim either tree until after it flowers on more than just the top

Some years ago I planted 500 "Meyers" that I grew from seeds. At the same time I planted 500 Meyers grafted from California. The grafted trees produced mature fruit in 18 months; but the seedlings did not make their first flower in 4 years. Eventually some of the seedlings produced fruit that seemed like Meyer; but maybe scientifically were not. The other notable thing was that some trees of the seedlings were taller, some were bushier, some had bigger leaves, and ALL of them had giant and numerous thorns.
Whether or not the seedlings were actually Meyers or not remains a matter of discussion; but they CERTAINLY were not genetically identical as are all the trees I produce now. I would not ever again try to grow Meyers from seeds; and to offer my first rule of trees... if you are going to plant a tree, you are going to put a lot of your energy, money and spirit into it; and you are going to have it in your life for a long time; so start with the best tree you can find/afford. It is kinda like buttoning your shirt; if you get the first button wrong, it doesn't matter how careful you are after that.