Ask replacement for Mercon LV?

According to the manual book, my car's transmission needs Mercon LV spec ATF. But it's kinda hard to find replacement for it, is there any alternative for it?
Other brand like Mobil1 Full Syn ATF and Castrol Transmax Multivehicle, said it already exceeded all Mercon spec, but I'm not sure.

Some friend of mine also said (owned the car as mine), the car main dealer used Castrol Dex 3 on his vehicle. AFAIK, Dex 3 has lower spec than Castrol Transmax…

I'm confused. If the they brave enough to use Dex 3 to replace Mercon LV, should Transmax be sufficient enough?

Need info
Thank you

PS: as far as I know, Dexron & Mercon is just "brand war/pride war" between GM & Ford… It's not funny that the customers became the victim of this business

Why are you confused? Use exactly what Ford recommends and problem solved. Why would you even consider adding any other fluid to your transmission and take a chance on doing damage. Transmissions are very expensive. In todays car the type fluid you use is critical to the longevity of your transmission. You can buy Mercon LV at almost any auto parts store and for sure at your local Ford dealer. There's no good reason and no excuse for using anything else.

Do NOT use any other fluid unless you have a spare $2,500 to rebuild the transmission. KY-CLAY is absol right. It's pretty simple. Buy the right stuff.

And you're wrong about the brand war. The latest versions of Dexron and Mercon are NOT the same. Very different specs and not interchangeable.

That's the whole point of my question, it's hard to find Mercon LV in my country, and the funny thing is, even official ford dealer, are like, giving up on these, they start using Dex3 ATF on our Mk2 (according to my friend).
If Mercon LV diffdifficult to find, how can I flush my trainy? I'm closing in 66.000 mileage, and I need to find the fluid that match the requirement