I think ppl didn't read the initial post entirely xD. The weekly savage/roullete will have a Pre-selected Raid or Extreme Trial for the week. So if it's Garuda Extreme, it will be Garuda Extreme for that entire week. If Its Alexander Floor 12 Savage then it will be Alexander Floor 12 for the entire week.

It will also start at 30% Echo buff and increase up to 50% Echo buff.

Since the Extreme/Savage raid is predetermined, anyone who's willing to do the roullete can just study the numerious guides on youtube before attempting it and win it. Not to mention the up to 50% echo buff and ilvl sync should help immensely xD.