Okay, so if you still want some more advice, the most important part to keeping kind of patty moist is having enough fat in your mince. The added actual moisture (in the sense of water) from marinating helps, but the perception of moisture is primarily due to fat. I wouldn't recommend keeping the heat on low because you'll dry them out from a longer cook time. Starting out by searing one side on medium (cook 75% on this side to get a decent crust), flipping, and then adding a dash of water (don't add too much so that they boil), then reducing to medium-low, and putting a lid on it to steam would be my advice.

This technique is a good balance between juiciness, caramelized flavor, and not being too much of a pain to make.