When working with exercises, the primary focus should not as much be on reaching a certain speed but a certain quality. Of course, with increasing practice, this quality will be maintainable also at higher speed. But "pace that's too slow before moving to the next exercise" sounds like you work on one exercise exclusively, then stop completely with it in order to start on the next.
That's rarely an efficient manner of improvement. While it makes little sense on focusing on too much material in raw state, "moving on" implies that an exercise has been exhausted and no longer contributes to your advancement. That's rarely an accurate view of exercises' potential for improvement.
The only kind of exercise where moving on fast makes sense if you are specifically practising your sight-reading skills.
For most other purposes, exercises will stick around with you for a long time. I think Rubinstein had a fixed two or three hour exercise regimen which he worked through every day while reading the newspaper and books.