To be fair Silence is the best choice of all four if you don't already have a good 5-star or 6-star healer.
Just to add, while you'll need to be lucky with the recruitment tags, Projekt Red is at least a guarantee with Fast Redeploy/Specialist and Crowd Control. Silence does not have tags that guarantee her. Even if you get Senior Operator and Medic, the pool is shared with Warfarin and Ptilopsis.
That said, I did choose Projekt Red for the name alone. The Witcher reference felt intentional. Now, I know she's a cute bundle of fluff and a useful assassin