No interactions present.
The first is probably a nymph of Chorthippus brunneus, but possibly Gomphocerippus rufus. The green one could be a nymph of Omocestus sp. or even Stenobothrus lineatus ... too early for me to tell. But the third insect I suspect is very small (little idea of scale ... 8mm long?) and so could be a common ground-hopper, Tetrix undulata. (Note: I'm not very confident about any of these identifications!)
All are found in South Devon VC.
Thank you for the comments. I will keep an eye on how the grasshoppers develop.
Lat/Lng: 50.6, -3.5
OS grid ref: SX9588