That's weird, I have a set of Fazer 600 coils in my hands right now and they are marked 1-4 and 2-3.
Also, when checking the coils on our sons 03 Foxeye earlier today, one coil definitely feeds plugs 1-4 and the other plugs 2-3.
It looks like we have a dodgy coil - bike running very rough, no fuel issues, 4 new plugs, but removing plug caps 1 or 4 when it's running makes very little difference, removing the caps from either 2 or 3, causes even further missing. Hence, I'm thinking dodgy coil (first thing I could think of that would affect plugs 1 & 4 simultaneously). Will put replacement coil on tomorrow - hoping its what's wrong.
BTW, this is the very first mechanical/electrical issue we have had with either Fazer (we've had the 1000 for 13 years and the 600 for nearly 5 years).