Toadi ah I understand now!
Yes this is a technique many artists who paint animals use. While on my animal painting study quest I found many artists doing this exact thing. Their reasoning was that due to the fast drying nature of acrylics, you can go over it as many times as you like in acrylic to get those fine details and then go back over it with oil to soften the details - in particular the fur. In acrylic it’s wonderful for detailing but it’s so hard to get fur that looks right. You either get one solid mass or it looks kind of wirey. If you look at my kitty painting in the holiday event you can see how it can look with just acrylic. You can soften those hard edges to a point but it takes a lot more time and energy than if you just use oil on top to finish.
The artists I have watched on YouTube can make those bold and wirey strands because they know that the oil they put on top to glaze will soften those lines. There’s one artist who is a favorite around here (someone help me out - she’s British and has a patreon account) who paints her animals all in monochromatic coloring to get the values and detailing and then goes back over in oil to soften and color. This lets you “cheat” by taking advantage of the benefits of of both mediums and the layering gives overall depth to your painting. If/when my lungs recover I want to try this technique but for now I can’t use oil. If you do try this my suggestion would be to paint with both and get comfortable with their properties before combining.
Always remember - you can paint oil over acrylic but never the other way around!