Yes, you should; Nizoral is part of the big 3, so it is always worth to add it (even though the effect of it is generally weaker than from finasteride and minoxidil)
My recommendation: If you only want to apply it to the temples, do not buy the shampoo - Ket works better if applied longer but applying a shampoo for an hour or more is not really recommendable due to the other ingredients;
There are creams that also contains 2% ket, I use fungoral and apply it directly to my temples
Cheers