Switching mains in the middle of gearing up, especially with new patches are never a smart move - as you mentioned, you're 2 weeks behind.

From what I've heard, the consensus for tanks in general:
1) Get the Lore chest piece (2 weeks).
2) Do not get the lore pants - get midas instead.

Here's something you can refer to: https://www.reddit.com/r/ffxiv/comme...2_1st_7_weeks/

I'm following one of the recommendation that allows me to complete 9 out of 11 upgrades in 3 weeks.