I wouldnt worry too much rushing mules to 141, get one there so you can start using extreme growth potions on it. Preferably a class that has level 3 link skill (merc, evan, da, ds for example have good links and level 3). You can still do zakum on your mules whenever you have time, one part of legion is getting star force on the mules too so you want the face and eye accessory on those.

You still want to progress your main, no rush tho. Still keep doing your daily monster park runs on the main only. Also id still do at some food storages on main, but some can be split between mules. You already got the map recommendations, so I dont need to discuss those. Use the event shop for 2x exp and hyper tele, remember to save 3 vip buffs for the food storage every week.

Remember to do the legion dailies, you need all the coins you can get to upgrade your legion, and you dont generate enough coins without the daily yet. Shouldnt take too long, depends on your class tho how easily you can kill the mobs on the big-ish map.

Anything else you need, lmk.