oh sorrry i misunderstood number 2 hahah meh bad
i think it doesnt really that matter as these accounts have different followers although some of their followers follow the other influencer too.
whats important is to test each influencer if their followers really bring traffic to your store. so maybe different influencer on a diffferent day will help with the tracking.
just my opinion though
i have spent $50 on trying IG shoutouts but havent made ROIs yet. haha