Yeah I think that the chicks will really like to be with the broody hen I'm really hoping on that other egg to hatch too I really would like to have three we'll see what happens if it doesn't hatch by Wednesday I guess I'll have to pull it
Some breeds tend to hatch earlier than others, and sometimes you get an overachiever or two... since you set them at the same time you should be ok and the chicks spending a day or so in the brooder should be ok, having an ecoglow style should make grafting even smoother if you decide to go that route.
If it is really warm the hen may not fuss much about a chick roaming and our hens don't leave the nest till day two or three and it isn't a problem since the chicks are good till day 3 after absorbing the yolk.