I’ll leave specific question on the Canadian system of government to the Canadians.
@Northern_Piper is usually very good. You would have read detailed posts on his bailiwick previously. I find them engaging and definitive. YMMV.
In the local situation the Australian Electoral Commission is non-partisan, despite that it’s three members ie the Chairperson, the Non-judicial Member: and the Electoral Commissioner are direct appointees of the Federal Government.
Electoral boundaries get redrawn after most elections, according to established guidelines. No Australian electorate has a regular shape, or even vaguely approximates one. In many cases the proposed boundary change represents not much more than snugging reflecting population changes. In other cases an electorate/district is merged, abolished or substantially moved.
Politicians consider the first draft. They (and other bodies with vested interests) can make suggested amendments. The AEC considers these submissions then publishes a final draft.
It is simply the expectation of the public that the AEC acts in a non-partisan way, in drawing the boundaries and conducting subsequent elections. No expectation that the partisan appointees will seek advantage or to win at any cost. Which political party has nominated any of the AEC board is not factor. Only an infinitesimal proportion of Australian would know, or care. The AEC task is expressly “to deliver the franchise: that is, an Australian citizen’s right to vote, as established by the Commonwealth Electoral Act 1918.”
There have been instances where the Electoral Commissioner tenure has been terminated by the government that appointed them because a batch of ballots went missing, even after they were counted and there was no impact on the result.
For most of the democratic west, this is an expectation not some pretense for these bodies. We, collectively would consider this to be entirely proper. If the US has carved out it’s own divergent, descending path and further deems that only US solutions will work for US problems I guess whatever consists world’s best practice, even merely general good practice represents a bridge too far. But it’s not hard, simply a mindset.
In any district/electorate with a diverse population distribution it would be a trivial exercise to construct an electoral map where using short, even straight boundary lines causes gross disproportional representation, even if not as profound as the grotesquely shaped boundaries commonly seen stateside where the politicians chose their voters rather than the reverse.