Cecil and Refia are the best available (currently) for tank and heal, so that's covered (Refia wants dualcast though).
Ling and Noctis are both excellent at their respective roles.
Arianna is really bad and should be benched. Lightning's your best option from that list.
That team is honestly very good. The only unit that's meh is Lightning, but when Lightning is your "worst" unit, you know you're in a good place.
The ranking site ranks based on 0 TMR's btw, which is the only reason Lightning is ranked anywhere near the top.