I used to take Adderall and Vyvanse. Vyvanse was added after the Adderall wasn't helping much; it only made my heart race. When taking them together they worked well for my concentration. Best thing was that I could wake up well in the morning and go to sleep w/o trouble every night, which I haven't done consistently since I was...ok never. I asked for a change because the monthly prescriptions were getting to be expensive (around $160 for the two alone plus I was away at school, unemployed). My doc told me to stop taking the Adderall and upped my Vyvanse dosage. Later on after I told her that I was feeling terrible, she told me to discontinue the latter and go back on the Adderall, which alone didn't really help my focus in the first place.
Before and during this period I knew nothing of the withdrawal effects. They were so bad I had to withdraw from classes this past semester (I went a little batsh_t...

). When I read more about tactile hallucinations (which I was experiencing) it came together for me that it was the med withdrawal that messed my head up. After that I stopped taking Adderall for good. My doc was mad that I abruptly stopped taking it w/o direction but that's what I did the first time on her order and resisted the urge to tell her to stuff it.
Overall Adderall worked best when combined with something else, for me. Everyone's different though. I probably should never have said anything in the first place because now I don't even have the attention span to return a text message lol. Just be in the know about withdrawal effects.
Yeah, sometimes short-acting stimulants work better if added on top of a base stimulant that's long-acting (in your case, Vyvanse).