Dealing with Doggy Sibling Rivalry
It sounds very normal and doesn't sound as if it's causing problems, so that's good. If it bothers you for some reason, I'd just teach them to be patient for a reward. For instance, if one if being petted, then you could cue the other to sit and stay. If he sits there patiently, you'd then lavish attention or treats on him for being patient. Right now, it may be that their pushy behavior works to get the toy or your attention. If you made patient behavior work for them, they would do that instead.