All of these are unproveables. People forget that WP came last from 1990-92, but even then had reasonable win-loss records and percentages. They had three bad years - but so did Subiaco and Swan Districts in the 1970s and no-one suggested moving either of those clubs back then. Clubs all go through a natural cycle of rise-and-fall-and rise-again. WP made finals from 1974-78, came third in 1982 and fourth in 1985. So overall the club was a reasonably strong performer from 1975-86 (or at worst we could call them an average performer). Flags could have been won at Leedy after 1993 - it is impossible to disprove that unless we find an alternative universe where West Perth never moved! (I would move to that universe if I could.)
Also, why not take a zone in the far-north but stay at Leedy as Perth Demons have done by keeping their home-ground in the extreme northern corner of their zone?
Alternatively, we can say that the club won premierships but sold its soul, a most unfortunate predicament.
Subiaco Scarborough was looked at in the early 60s (there is a photo somewhere of Subi playing coach 'Spud Slater' in the proposed jumper) . Subi would have moved to a developed Abbett Park.
Its called progress, like the national comp.