There is a chance that:
1. The Espinal/Biggio platoon at 2B is extremely good
2. Merrifield is a stud 4th OF
That is kind of how I like to think about the roster - with Merrifield as the RHB 4th OF, ostensibly on the bench. Of course he can and will play a lot and play 2B too.
If you think about it like that then a RHB OF for the bench seems like a luxury and not a need, whatsoever.