Got home and looked, Ancestry.com image check shows 1,644 Whites in Lawrence KT in the 1860 Federal Census. Again the enumerator specifies "City of Lawrence" on the header. This matches very well to the Junior High kids project numbers you have posted. So the two towns were similar in size and I think it safe to say Quantrill was certainly the more brutal of the two in terms of deaths. Lane likely got away with more material wealth.
John R.