Can you feed more often, but smaller amounts? It would be good for the one who grazes as they can get pellets more often without having to worry about them all getting eaten.
You can also try putting the dishes in different parts of the cage. You can train them to each go to a bowl. This would only really help for a short time after feeding as they would go to the other bowls. Probably more of a help if one rabbit tend to eat all the food and pushes the other rabbit away.
Putting pellets so they are not in a bowl might help. You can get a cardboard box or toy and put the pellets in with some hay. They should still eat the pellets, but it will take longer for the one who gobbles them up. As long as the grazer still knows where the pellets are, then they should be able to eat them. It would be hard to monitor who eats what though.
More food dishes can help too. Only put a small amount in each dish, maybe 1 table spoon or so.