Cúchulainn is not pronounced 'Ku-kullin' - it's 'koo-hoo'lin'.

Gráinne should certainly not be Anglicised as 'Grace' - it does not have any equivalent form in English. The pirate Gráinne Ní Mháille became known 'Grace O'Malley', but that was through ignorance, not enlightenment.

Óisín is 'Osheen', not 'Usheen'.