that original original Loki didn't interact with anyone (well Thor) and it was an apocalyptical event in that everything (ex. Thor) including copy-Loki's body was destroyed/lost/killed.
using ep .2 rules that means the Loki duplication yields no variance energy.
Richard E. Grant could have been written as just any other Loki BUT for dramatic effect including variance-Loki meeting the (de facto) "superior" original original Loki, it was better to make Grant that original original.
some 
1.
ep 1. ts = 26m04s
loki: i know what I am
mobius: what? a murderer?
loki: a
liberator
["liberator" == foreshadowing of loki "liberating" ... explains richard-e-grant-loki's reasoning. he is liberating from the dominion of the TVA]
2.
ep 1. ts = 26m33s
mobius: let's talk about your
escapes
mobius: you are really good at doing awful things and then just getting away
d.b. cooper story ...
mobius: let's get back to escapes. what is it that you think you are running from
[escape ability stressed - to bolster hidden escape from thanos]
3.
ep 1. ts = 30m07s
loki: i am on the verge of acquiring everything I am owed and when I do it will not be because it's supposed to happen or because the TVA allowed it. you are a detour in my ascent.
[almost the words of richard-e-grant-loki and how he can do what he is doing outside of the control of the TVA]
4.
ep 1. ts = 32m44s
mobius: (to loki) so that others can achieve the best versions of themselves.
[grant-loki helping others including other loki's achieve the best
versions (plural!!) of themselves]
5.
ep 1. ts = 39m25s
[shock on loki's face when he thought he had been killed]
ep 1. ts = 39m38s
[contemplating and calculation on loki's face where he realises that his original had escaped thanos]
ep 1. ts = 40m0s
loki: laughing out loud at the fact that his other self had escaped hidden to all
hunter B15: (to loki) what is so funny
loki: (to himself) glorious purpose
[loki realising that his other self had outsmarted everyone and the implications of that. mind was ticking]
ep 1. ts = 42m30s
[loki starts playing the long game with mobius as he now knows that the TVA doesn't know everything. his behaviour switched up when he realised that original loki had already escaped the TVA.]
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