Ryan & Matthew are both good looking men who are looking for the good looking woman who (they think) befits men of their "status". Robin is beautiful, clever & statuesque and both men feel they deserve her. But they don't know her, they don't listen to her, they resent her work, and both feel inadequate in the shadow of Strike.
Robin uses both men as shields - shields from her trauma, her self, her love for Strike which she feared might blow up the one things she is really honest with herself about loving - her work/business.
The fertitlity story is interesting - we are all conditioned to wanting children as a default, but many women increasingly don't want children, or lack any drive for children. Lacking an internal drive for children doesnt necessarily mean a woman doesn't want them - she might just have other things on her mind, as is the case for Robin. Its only Robin making these decisions now - the chaps are all OK. Women are forced into these decisions - while our "equality" and place in the working world advances, women are rarely if ever able to be liberated from their biological bodies. The clash between career and family is still very real - neither Matthew or Ryan face these dilemmas.
I call THM the "baby book" - babies everywhere:
Decima
Bijou
Isla
Vanessa
All the Cunliff babies
Sarahs babies
The new puppy Betty
Plugs puppies
Contrast with Wardle who has his toddler overnight while the mother is out.
Not thought this all through yet but in TRG we saw baby farming & traffiking & the complete dismissal of "mothering". In THM the babies are essentially wanted & loved by their parents (there are some complicated situations too) & all are mothered.
Silver is a traditional gift for new babies.