So we have two Tornadoes closing around 14nms/min at 500ft, and one gets "climb, climb now", and the other poor sod gets "descend, descend now". This is the very reason why AAIB advised in 1994 that TCAS was unsuitable because "It resolves conflictions by advising manoeuvers in the vertical plane and this would be inappropriate at low level"
Given the rate that a Tornado can climb at low level, does it matter if the other cannot descend much?