I personally love the strip method Of HSTs. I have the Creative Grids 4 in 1 ruler. For 4.5 hst (finish at 4...which is what I think you have) cut strips at 4.5. Layer 2 pieces of fabric then up/down cut to make pairs. Then sew like leaders and enders.
I used this method on my churn dash ....and I didn't need to square! Takes off 1 of the dog ears too. I think I got 16 per strip with very little waste. Try with scrap first.