Actually the FR235/640/735 has a 45mm diameter, the difference being that the lugs don't stick out like on the 5s and it's a lot thinner too at 11.7mm vs 14.5mm.
I'm still curious too see what that a 42mmx14.5mm watch with lugs that stick out a lot looks in the flesh. I'm sensing that it might look a bit odd...
Where did they say the 5S was for women?
And this : https://the5krunner.com/2017/01/05/garmin-fenix-5-for-women-girls-and-other-members-of-the-lesser-sex/ ;-)
As for the ratio it is in fact quite different :
5s : 42 over 14.5
5 : 47 over 15.5
5x : 51 over 17.5
17.5mm is humongous, the 16mm of the F3 were bad enough...but 14.5mm is a lot for a "small" watch, but yes, will have to be seen in the flesh and tried on before deciding.