We consider how the idea of a Germano-Persian kinship was rejected particularly in the British circle of scholars centered on Brian Walton’s Polyglot Bible, (1654). We first treat of the context and main issues of a discovery which could have opened the road to a precursor of modern Indo-European comparativism. The diversions or disroutings took various forms: comparative parceling (John Greaves, Elementa linguae persicae, 1649), reversion of the parceling (Edward Bernard in Hickes’ Institutiones grammaticae anglo-saxonicae, et moeso-gothica, 1689), war-contact hypothesis (Thomas Hyde, Historia religionis veterum Persarum, 1700), grammatical occultation (Angelo à St. Joseph, Gazophylacium, 1684). However, Marc Zuer Boxhorn’ precursory views about the Scythian origins are kept alive by Brian Walton). We include those diversions in Leibniz’ thinking as reflected in his correspondence, especially with Johan Gabriel Sparfwenfeld (Leibniz Bref till Sparfvenfelt 1695-1700, 1883).