Use an armature to animate your mesh.
Above image is a weight painted mesh. The red submesh (letter R shape) is controlled by the bone with a corresponding vertex group. The fine connection lines of the armature are hard to see.
Below is the mesh reshaped by the armature in pose mode.
Animation to follow. Perhaps you can show an animation for me.
Multiple meshes or single mesh. If an armature can animate a body mesh it can animate your mesh. Each letter can be assigned to single bone exclusively via vertex groups. All meshes can have vertex groups. The armature is a sequence of controllers for your sequence of mesh/submeshes.
Bones of the armature can be disconnected so they operate independently in terms of rotation and position, yet are a convenient collection of controllers.
We assume your 3d text type has been converted to a 3d mesh type. Thus I will only use the word mesh.
Bones can operate on an entire object, or an entire mesh, or parts of mesh, and share influence. Those features are intentional. The parts of the mesh can be designated with vertex groups. This often automatically happens with ... parent to armature. Then weight painting creates modifications.
Each mesh or submesh (visually looking like anything including a letter) can be in it own vertex group assigned to a single bone. Bones which control the head of a body mesh do not control the toes, there is independence.
I will submit a picture in a few minutes. You can submit one in addtion in your question.
You would edit position in pose mode of the armature, and have access to all armature features.