The loadout recommendation for that mission is the loadout "recommended by Basil." This solely means that Basil sells those recipes in the Mission Lobby of Plan of Attack. It is not a loudout recommended by a player, or by the person who wrote that page in the wiki.
In fact, I would say that the loadout recommended is fairly bad (at least the weapons and shield are), and you should take other wiki pages with "Basil's recommendation" with a grain of salt.

An armor's defense generally matters less than its offensive bonuses, though. If you use swords, then bringing Dusker gear would be good. If you use guns, you should bring gunslinger armor. So the armor recommended is fine.
Your primary consideration when choosing a shield should be the statuses it resists, then what damage type it defends against. Brute Jelly shield isn't a great option for this level (or ever, really) for that reason. You would want a Skelly and Owlite shield for this mission, but shields aren't really a priority when getting new gear, so I wouldn't recommend getting one if there are other things you want more. You could also bring a Swiftstrike Buckler or a Thorn Shield for its offensive bonuses.

Weapon wise, just bring a pierce and elemental or shadow damage weapon. Rigadoon is fine, it is just outclassed by swift flourish as its stun has a low chance. Magnus is also fine, but it's slow and it will be difficult to hit fiends with. The bombs are not recommended: they will take a long time to charge at this point in the game, and Shard bombs are not very strong. Also, Toxic Vaporizer is nearly useless in the first level, and the blast radius is very small.

A 3star loadout I would recommend would be Dusker Cap and Coat, Swift Flourish/Twisted Snarble Barb and Elemental Blaster, and the shield is up to you (I'd personally bring Swiftstrike buckler, but thorn shield or skelly shield are also good options).
Flourish is good for dealing with fiends and gremlins, and blaster is good for picking off enemies from a safe distance, and gives you a weapon to help deal with the construct enemies that typically pop up with gremlins.