Beware of too MUCH contaminant depth. 'Deep' water provides a significant deleration force. It is the poor to nil braking action you need to consider.
The issue is clouded too by talk of '727's landing on short runways with ease - so what? Some 727's had nose-wheel braking, and as TB says, the reversers were very effective by comaprison. Comparisons of a/c speed on the video cams too may be misleading, although dramatic. EG We do not know, I think, anything about the weight of the first a/c, do we?