I'll add one clarification to my own comment: if you should choose to have rating scales completed, make sure they are completed by both last year's team and this year's team, for two reasons: in order to have some reasonable confidence of validity, the rater needs to have had daily, substantive contact with the child for a minimum of a month, preferably two or more. I typically go back to the previous year's teaching team for ratings completed during the first two months of school. (But I also work in a secondary school, with fewer minutes of teacher contact daily.) And in your case, you would probably want representatives of both sets of teachers because their perceptions are so contrasting.
