Sorry to cause some trepidation. No harm meant!

The arrow will normally not be at a 90 degree angle. For me it is generally 5/8ths above square for best flight. You should not have to shoot three under if you do not prefer it. Tune the arrow to your shooting style. Don't tune your shooting style to the arrow.   I would fletch a few and do some paper tunning. Tuning with paper is often easier for those just starting out.