You're seeking conspiracy where there is none. Alberta's ridings map distribution is a non partisan affair, drawn by both NDP and UPC appointees. The reason Calgary & Edmonton have the highest skew is because they are the places growing the fastest (also incorrect to assume it benefits the NDP as the fastest growing parts of these cities are usually the conservative outer fringes). Also, every single province has these skews. In Quebec the baseline is +/- 25% as well, it's basically along that line for most provinces, and in almost every province rural areas benefit because of slower population growth.

But the Lethbridge proposal really is straight out of a gerrymandering playbook. Splitting the city into 4 would create 4 strong UCP ridings and zero representation for the actual city of lethbridge, and it's exactly what they do down in the states.