The verdict
For a small B2B team, I'd pick Figma. It runs in the browser, there is a free Starter plan to try it on a real project, and it is the tool most designers and freelancers already know.
Pick Sketch when every designer is on a Mac and you value a fast native app. Free viewers and free developer handoff on subscriptions are a real saving, because design tool costs usually grow with the number of people who only need to look.
If your team is mixed across operating systems, or stakeholders need to edit in the browser, Figma is simpler. If the company already works in one of them, follow that.