The hand feeding is a really good tactic. You don't need to eat before them or anything. They understand that you're a human and not a dog.
Luckily resource guarding is easy to correct if you have some time to spend. Basically, you teach the dog that all good things belong to you and all good things come from you to them.
There's a training philosophy called Nothing In Life Is Free (NILIF). It operates on the premise that the one in charge is the one that controls the resources. Resources can be anything the dog wants, like food, toys, comfy furniture, ear rubs and chest scritches, etc. It's very positive, disciplined, and doesn't involve punishing or intimidating the dog.
When I bring home a new puppy or foster dog, or have an older puppy going through the obnoxious teen phase, I'll put them through a strict regimen for a week or two (depending on the dog and what behaviors need establishing and modifying), then relax a bit and let them find their place. So far it's worked extremely well.
Basically you put his daily portion of food in a bag in your pocket. Then you put him on a leash and tie it around your waist. The dog must earn his food, kibble by kibble, throughout the day. That doesn't mean he has to sit 500 times a day. Just slip him a few kibbles every time he does something you like and want him to keep doing, whether you requested it or not. Stuff like, ignoring the other dogs eating, being nice to or ignoring cats, calmly watching children, sitting next to you on his own, looking at your face when you say his name, pottying outside, etc.
This teaches him what kinds of behaviors you like. It teaches him that all the food comes from you. It builds a strong bond between the two of you.
Teaching him the "trade" command is really good for resource guarding too. He's guarding it because he's afraid he's going to lose it. If you give him something low value, like a cool toy that he likes, then offer something fabulous like a hotdog and say, "Trade!" he has to release the toy to get the better thing. Then after he eats the hotdog, give the toy back. That way he learns that he's not losing it forever. When he understands that, you can increase the value of the trade objects. He'll get to the point where he'll willingly give you hotdogs from his mouth. I used a modified three way trading game to teach my two not to fight over food. Now they'll chew on the same bone together and eat out of the same bowl at the same time by choice.