Byddai gan y cynghorau rywfaint o hyblygrwydd ynghylch y patrwm daearyddol i'w ddefnyddio wrth rannu cyfrifoldebau dros wasanaethau penodol eraill gan gynnwys gwella addysg, gwasanaethau cymdeithasol, anghenion dysgu ychwanegol, amddiffyn y cyhoedd a hybu'r Gymraeg.
Councils would have some flexibility over what footprint they use to share responsibilities for other mandated services including education improvement, social services, additional learning needs, public protection and promotion of the Welsh language.