Only 3500 grafts for the top and crown may not be enough.
Post some pictures of your head.
Always ask (or understand) how many grafts you have lost before planning to estimate the grafts to be put in.
Long ago, even top doctors could place only 4000-5000 grafts no matter how bald you are.
Now, we can place 8000-10,000 grafts for most patients.
Logically speaking you should look to REPLACE the maximum number of grafts that you have lost.
So, asking anyone "how many grafts are good enough" is pretty lame in the present time.
Check yourself out (your scalp and beard donor atleast) and if you have lots of grafts then plan for more.