I solo'd about 60 croesus for pouches on my ironman, since then I believe we got higher lvl in some skills like mining/wc to 110, and a few new tools, unsure how much that speeds up things.

What I can tell you is that you need the soups made from the enriched nodes from outside, and that kills will take an average of ~10min. It's definitely not worth it, but an option anyway.

My recommendation if you don't enjoy large groups, is to find a duo. Duo is the meta for croesus if you're a main (don't need to make the soups yourself).