With only 1500V and dirt from steam locos it would seem necessary (and sensible) as the leading one could act as a wiper especially in wintry conditions.
Some screenshots from the route I've been building for the last few years, which will come out within the next decade or two...
I was playing with the LMS Circuit from Golden Age Developments https://www.golden-age-developments.co.uk/lms-circuit.html But I have a dislike of Kettles (Steam locos) so I swapped to BR Blue
ScotRail 380010 takes charge of the 20:51 Glasgow Central to Lanark service, seen coming out of Wishaw on 6th October 2026: