Dynamic[Row[{Slider[
Dynamic[splits[[1]], (splits[[1]] = Min[#, splits[[2]]]) &], {0,
Mean@splits}, ImageSize -> {5 Mean@splits, 25}],
Slider[Dynamic[
splits[[2]], (splits[[2]] = Max[#, splits[[1]]]) &], {Mean@
splits, 100}, ImageSize -> {500 - 5 Mean@splits, 25}]}],
SynchronousUpdating -> False]