I know it sounds weird, but the rule is clear IMHO. If any element contacted on its flank can give rear support in any bound, then does not turn. I think none would turn in your example and the first one would apply -1, but a clarification here would be extremely appreciated
If you look at the DBMM v2 Commentary it has a clarification.
Contacting a Second or Subsequent Enemy Rank in the FlankSee the figure below. If a friendly element (B in figure) contacts the 2nd or subsequent enemy
rank in the flank (Z in figure) while the enemy front rank (X in figure) is fighting a friendly
element (A in figure) there are two possible outcomes before combat is resolved: (a) the rear
rank turns to fight against the flanker or (b) the rear rank stays in place and the flanker counts
as flanking the first rank element (X).
If the rear rank(s) contacted could provide support vs the current frontal opponent in any
bound then they do not turn to face (for example if A was a Knight and X and Z were Spear).
The contact with their flank is counted as contact with the flank of the enemy front rank
element. If the rear rank(s) contacted cannot provide support vs the current frontal opponent,
they turn to face the flank-contacting element and will fight their own combat.
(the figure is on the page 35 clarification, open the pdf below to see it)
http://dbmm.org.uk/images/playaids/dbmm%20commentary%20v5_0_6_condensed.pdfBest Regards
Geoff