A small trick that you can do is to create a matrix of either of those 2 vectors and then paste the matrices like below.

Just a small trick,

Suppose the matrices where letters = c ("a","b","c","d") and numbers = c (1,2,3,4,5).

Now create a matrix of any 1 vector and then paste matrix with the vector this will fetch you combined vector as you wanted.

Pasting 2 vectors directly will give result as below