I think there should be 2 options on which to upgrade your english infantry to, the english billman (who should all have bills as there weapons by the way) and the second option should be dismounted english knights who were very common in english armies because being dismounted gave them the chance to protect there archers. Oh Year speeking of archers English longbow should upgrade to english Yoemen (sp?).
I hope you implement these minor changes, cheers.