Regulated Utilities Valuation Techniques

Hi everyone,

I am currently analyzing a leading engineering and construction company (SNC-Lavalin Group) and I am trying to understand how analysts are valuing its spin off AltaLink (largest transmission network in Alberta). I discovered the EV/Rate Base valuation method, but I can't exactly wrap my head around the "multiple of regulated Equity Analysis". Apparently, the EV/Rate Base method doesn't account for differences in allowed equity thickness amongst utilities and this other method should be used in conjunction. However, I can't seem to fully understand what equity thickness represents and how you account for differences between regulated utilities. I would be very grateful if someone could help me out here.

Thanks

PS: Attached you will find the table I am trying to understand.