Q: Cu Chulainn and Diarmuid are both Lancers, but who will win in an honourble battle? In their first engagement with Saber, Cu Chulainn was being pressed hard, but Diarmuid was able to pressure Saber. So... Diarmuid is stronger

A: Diarmuid received more backup from his Master (magical energy supply), thus in terms of pure firepower, Diarmuid was stronger. In Japan, both of them received 0 geographical boost (from the cultural sphere), but if the stage was in Ireland --- Cu Chulainn would have an edge.

Comptiq 2007 Issue 6; Fate Dojo Q&A