I'm not aware of any recent studies or indeed any currently active researchers that advise against periodisation, it's the underlying training principle in every sport.

I think strength training is important in endurance sports as it gives you a higher ceiling such that the lower level stress becomes a lower percentage of your max strength, i.e. it's easier to run at 60% of max effort than at 70% even if your pace is the same in both instances.

The Lydiard training principle sounds very much like polarised training: roughly 80% base in Z1(recovery) and Z2 (endurance) with the remaining 20% being high intensity.