Their is plenty evidence, to put forward, how ever let's touch slightly on some.
In evo in clay day, Taurtis is here, and I'm up to no good (the second half). In clay day Grain keeps Taurtis safe from mobs and corrects him when he takes to much cactus. In I'm up to no good he traps him. And he shows him around in Taurtis is here or video 13.
Also in the gang beasts videos he keeps him safe from the green guy quite often.
In build swap they have a few videos of them just interacting softly or working together.
They also have made sea of thieves, and shift happens videos together where they work with each other.
And they have even made one or two, machinemas together as well.
