The Navy has made some strange choices for ship names in recent years. Given their role, Vengeance and Victorious for two of the Trident Boats was a strange choice
No, not really, since the Ships Names Committee would have been very mindful of the fact that, consistent with the tradition of classing submarines in broadly alphabetical order, albeit not exclusively. For example, the last four submarine classes built have been R for RESOLUTION, S for SWIFTSURE, T for TRAFALGAR, U for UPHOLDER, hence the need for names beginning with V for what is effectively the V Class.
Appreciating that the last of that name was a light fleet carrier, I feel that VENGEANCE sounds a particularly appropriate name for an SSBN!
Jack