I never rely on skinks to charge anything anymore. They have trouble taking out war machine crews . In my first game I charge a unit of goblins in the front and in the rear and got eaten alive, on a separate occasion I sent a unit of 10 skirmishers after a war machine and they held for 2 rounds. Granted they held up the war machine from shooting, but I lost like 3 skinks when I could have just shot it down. As for the razordon vs salamander, I always choose sallys, they are just too good. I faced a person playing brettonian knight in lance, got template over 60% of the models and (after a healthy dose of iceshard blizzard from my skink priest) got them to run off the table 1st turn. The problem with that situation was that in lance formation the models at the end are right next to the table edge, so even the roll of a 2 would get them off the board.
I think if there are any buildings on the board I'll have the skinks occupy it and shoot and anything the comes near.
I think salamenders are very good in the center of a saurus army. Three salamenders will burn the enemy elite and saurus warriors will do the rest.