Hardly surprising as the show is conscious "casted". Darren Day was probably cast more in the usual role of "person whose star is in the descendant" but when he went in, with his schtick about being a love rat, they realised it was better copy. So now "middle aged love rat from the 1990s' media" is now a role, and they cast to the role.
Darren was my favourite HM by a long way, but Grant doesn't look too promising - yet. Things might change as they settle down and he gets more airtime.