How do I know where to out the little plastic spacer rings in my cassette

So I'm a muppet and didn't pay enough attention when removing my 11 speed cassette (it was a bastard to get off!)

I seem to have an extra spacer and my tiny cog still threaded onto the freehub body, so I decided to try stacking it so the spacer sits in behind everything, pushing the entire cassette out ~2mm - hoping that improve the miserable chain line, somewhat

Am I mad?

To be fair, the tire and rotor arent back on the wheel yet, so once I get it in the frame and the chain on it might be painfully obvious