What @Abambo, said. Setting up a team account with you and your two designers will solve this. The team subscription will make it much easier to collaborate. Our customer care team can help you set this up. With a team you can have two Creative Cloud "seats" and as the team administrator you can assign each of your designers and then add an Adobe Stock subscription to the team. You can assign the Stock "seat" to yourself or one of the designers. Then everyone on the team will have access to the Adobe Stock subscription, you as the team administrator and the two designers because they are assigned to the Creative Cloud products. Plus the Stock subscription will be integrated within the two Creative Cloud applications. Your designers will be able to search Stock from within their applications without going to the web. No one will have to use your credentials to sign into the Adobe Stock site once you set up your team. You will want to change your password though. 🙂
Contact customer care here: https://helpx.adobe.com/contact.html Click on the chat icon in the lower right portion of the page. If you are unable to see this feature you may need to scroll down before it will appear or set your browser to private or incognito mode. You will need to cancel the personal subcriptions for you and your designers and customer care can assist with this also.