Saurus warriors can stand up and survive most any charge allowing their reserves to get stuck in and break that enemy's rank and will. Saurus Warriors are extremely suceptible to initiative based magic. Some of the best cheap regimental troops out there. Use in small units and skirmish. Extremely fast with M6, these guys will screen anything from your stegadons, cold one riders to kroxigor units.
Aquatic ability can be a lot of fun with the right terrain, especially a river.
As skirmishers, skinks make wonderful screens for your flanks. Skinks. . . Meanwhile, the enemy runs into a nasty set of saurus spears. The skinks next turn will of course rally and be able to charge the following turn, if the sauruses can't break the enemy in one turn. By holding some skinks right behind your main assault forces.