Well, I don't want to traumatize either of them or risk their health, so I figure, always better to ask. Thank you for being so helpful! I did some online research, but it wasn't very helpful, so I thought I'd ask here, which turned out to be much more productive.
One more thing is, I don't have any other horses his age. I just have his mom and two horses aged 3 and 22. I have heard that it's best to have a weaning buddy, but I'm unsure as to whether it's best to have another weanling or whether an older horse is just as good. If it's best to have another youngster, I can probably make it happen, but if older horses are fine, then that would definitely be more doable for me. Does it matter that much?