I don't think Caucasians have worse results than other ethnicities. For instance, I am Caucasian and I've had wonderful results from 5ar inhibitors. If there is a difference, I'd say it is negligible. After all, it is a fact that humans are 99.99% the same genetically with greater variation within subgroups (e.g. all white skinned people) than between subgroups (e.g. Asian and white). In my opinion, race is for the most part a social construct.
Anyway, back on topic, original poster you definitely do need to take finasteride. Minoxidil appears to work primarily as simply a growth stimulant. There is some evidence that it also interferes directly with the underlying balding process through a different mechanism, but the extent to which this property of minoxidil is able to be effective in terms of stopping hair loss is not known. Basically, you do need finasteride to be sure that you are treating the underlying balding process efficiently.
A previous poster mentioned RU58841. If you find you have bad side-effects from finasteride then you could try RU58841 in place of it. RU58841 is not as effective as finasteride, but it is something to strongly consider if you find you can't tolerate finasteride.