Center an object to another object?

This one is causing me headaches. I’m designing plaques with various text on them. I’ve created the plaque, and now I’m creating multiple extruded text objects.
I just want to quickly align them along the X and Y axis (red/green) so that the text is centered on each plaque, but it seems that Sketchup lacks this very basic functionality.

Am I missing something?

It would help if you add an example model.
You can use the midpoint inference to snap two things together.

Yes. As Box indicates it would help us give you succinct advice if you share an example .skp file.