Banishment forces rerolls of successful ward saves so that Light spell can thin them out while you are waiting for them to get in CC range.
A Salamander will do okay, though they will drop half as fast as other elves, they still have to take their Panic test (which they will probably pass unfortunately).
In close combat, Phoenix Guard do not drop easily with their mighty Ward Saves. The Lizardmen list really doesn't have anything that can take Phoenix Guard out one-on-one (unless you have VERY deep ranks and are willing to play attrition or are able to get Speed of Light AND Birona's Timewarp on them), so I'd recommend flanking the Phoenix Guard with something, a Skroxigor, Stegadon, Cold One Cavalry, or if you are in a pinch a Razordon or Salamander.
Speed of Light should probably be used on whatever is fighting the PG, that'll deny them the rerolls from ASF and make them hit your Sauri on 4s instead of 3. That should drastically reduce the number of casualties you take. Pha's Proteciton and Biorona's Timewarp will help you too but you probably don't want to load up all your buffs on one fight. Since some are bound to be dispelled, why not lead off with Timewarp to draw out the dispel dice? The number 6 spells tend to instinctively worry players.