Good point! To be honest, shamefully I hadn’t watched @musicalbox’s great tutorial before I posted!. Text clips are fine!
Having said that, making your own PNGs might be advantageous because you can add a border, or other design, and maybe custom positioning, to your counter. Depends on how much time/effort you have available to put into it!
To go even further, you could also make a short animated MOV when the numbers maybe “bulge” (ie enlarge then contract) - like in this demo showing short examples of one of my recent music videos:
… however, this may be overkill! 