I’ve had something similar, Coleman version, similar sized, but the same set up of rooms either side and a space in the middle.
We(me and mate) found a better set up which was to only have one room(I had my vango F10 mk2) and the area we had without that bedroom did nicely for a large table, flat stove and storage space. It also meant we could both sit comfortably beside the table in the evenings, without being somewhat crushed in, especially with 2 large dogs.
Putting up was a pain initially, a few strong words back and forth 😆 but in the end we cracked it. Basically get all the poles in, bend and set them, then peg out. Needs to be able to move to get the poles fitted, even if that means it blows about a bit. Pegging even a corner limits it from moving and might put too much strain on one area, which we felt could lead to a rip.
Putting up we fitted all the poles, the middle cross and the straight ones for the rooms, then did the middle cross first, then the outsides. Its more or less up with the middle cross sorted, so you can peg that area with a couple of pegs to stop the wind snatching it away.