I had a similar question and my original thoughts were confirmed. It is ok to use both. first use acrylic, then enamel on top after at least 24 hours of drying time. Also, try to have the enamel be the darker color for when you are doing camo you should start with the light color and follow with the dark. I've never mixed the two together to try to get a color and probably wouldn't recommend it.
Another rule of thumb, never put flat on gloss, but it is ok to put gloss over flat.
Lastly, be sure to put on a coat of matte or flat coat before you begin to mask for camo. Otherwise, the paint from the first color might lift off when you remove the mask.
Dan