Def replace Leia. Your team already has good dmg output with wiggs and ezra. The dmg you lose would be more than made up for by the utility of R2. He'll increase all your toons stats, negate dodge with his burn, stun very often and soft taunt/stealth your team. Ezra is the better option to keep as he can call assists and dispell irritating buffs such as taunt. His utility is more important than the small dmg boost keeping leia would offer. Ezra has synergy with R2 as well as leia. Although Leia does benefit from R2s stealth, Ezra can target R2 in an assist for a stun. Call wedge for dmg to get a kill, or if you wont manage a kill, call R2 for a stun.