と[共「とも」]に => Both, at the same time N2
Information, Report
も[同然「どうぜん」]だ => The same as saying A, as good as A N2
Adjectival, Descriptions
[一方「いっぽう」]だ => Change A continues, A does not stop N2
Miscellaneous
[一方「いっぽう」] => On one hand A, on the other, B; Although A, at the same time, B N2
Contrast,Surprise