I get that GLAT is the latest and maybe most appealing because of that when I started I chased the latest at the time for my first GL, JMK. There was only R8 at the time and I had to develop my roster to move to a guild capable of CPIT so it took me a while, but that’s with perspective of it being my choice and other GL’s were more readily farmable. But now there is sooo much choice of first GL I am not even sure she would be best to initial chase.
I am assuming you are an early account because R9 mats are more available than when they were first required for a GL. Many like myself already had the Ashoka’s at R5-R8 so they were much easier to level up and maybe why they were set so high. So, yes it requires 3 R9 but they were much easier to achieve with a decent raid performance.
The estimate you made is not entirely true either if you work on your raid performance over that period you will earn them more efficiently over time, all high relic mats are achievable that way and with personal track you don’t necessarily have to move guilds as many had to, to achieve higher relic materials in the past. Many moved guilds for R8 and R9 mats in the past but now you can focus on your personal track. Or move to a guild which earns more and focus on your personal track for even faster progress.