Beside maybe, Yuna and Rem that are straight up garbage, most weapons are nice bonus and now that CP is a non issue, i'd advice to get WoI for any char you're seriously investing into(if your PS situation allows you to). Although, I would do that on a case by case basis when the chars cycle in relevance again. Most of them aren't great pick for recent content, so there's no rush.
Squall and Hope are decent personal buff : https://dissidiadb.com/squall/sol_blade https://dissidiadb.com/hope/aile_blanc
Zidane/Bartz/Laguna/Edgar are all small aura, with easy to meet condition : https://dissidiadb.com/bartz/noir_calibur https://dissidiadb.com/zidane/verdant_slasher https://dissidiadb.com/laguna/hellblau_gun https://dissidiadb.com/edgar/schwarz_lance
I feel none of them match the level of utility you get out of cloud. But all the small auras with relevant stats helps when you'll bring those units in tough content.
For now, only Squall and Cloud are in decent spot, don't think Zidane will be a hit with lvl 70 in a few days since he gets no EX+...