I have that problem with Jaden and Jewelina, I free feed as well and use the Canidae's All Life Stages but try to keep them out of each others bowls so I have an idea as to how much each one has eaten that day.
I've done two things that seem to be a little helpful, maybe they'll help you as well. I use different size bowls, Jaden's is much bigger than Jewelina's so they can tell that they are different. I also try to keep their food in a room where I'm at so I can see both of them and if they go to eat from the others bowl I'll pick them up, say no in a firm voice and bring them to their bowl and offer a piece of kibble from there and they kind of get the idea that there supposed to eat from their own bowl. "Supposed to" being the key word here...they still try to sneak a piece from the others, I think it gives them some kind of thrill like they are robbing a bank or something except it's a food bowl
Anyway, the newest thing I've done which seems to be helping the most is, I have Jewelina's bowl on a rubber mat, Jaden hates the feel of it so he won't go on it at all. Jewelina on the other hand could care less so she will. I keep her bowl on there and that keeps him out of her bowl, Jewelina on the other hand is deathly afraid of Jadens squeaky toys for whatever reason
So, I've placed his squeaky toys all around his bowl and she stays away from it. Maybe something similar would work for your boys...you could always get a Moose to stand by Jack's bowl to keep Eddie away
