The build itself in the guide is very good. The reason why people use EOH on Celesete(even the pros, no joke) is because Celeste needs all the energy. Even with Halcyon Chargers(which most likely will be your last item) Celeste can only spam so much Helios.

Max Energy=700-750(around that)
750 dived by 50 = 15
lets say you had energy regen with clockwork and Halcyon Chargers, and the cooldown of Helio is 0.94 sec(30% cooldown speed)(one helio persecond)
energy regen= 2.53+4+7.5=14(approx) energy per second
750+500= 1250
1250 divided by 50=25 helios
25*14=350
350 dived by 50 =7 helios
32 helios in 25 seconds. You can't spam that much so eve is very useful, with even more energy regen for her(18), more energy(1500), etc.
It is simply reliable.
Maybe you can add reasons why you think EOH is shiz item? The added lifesteal also gives Celeste more sustain, which she SOO desperately needs(with a health regen per second of 2.23) Eve synergises very well with Broken Myth, as you can see(sustain for long fights enables more stacks).

Other than that, you can decorate your guide and add more detail(gameplay, etc)

All in all, It is a good guide:) It has potential to be really good:)

PS: Sorry for all the math. I can't find a way to explain it better. I hope you get what I am trying to say.