High turnover could be due to a variety of reasons. It could be due to pilots leaving Hong Kong as soon as their bond is over or have enough hours on type (screw the bond). HKA is pretty sick and tired of such pilots but there's nothing it can do as bonding is illegal in Hong Kong.
The solution lies in recruiting those who already have long term ties or commitments to Hong Kong. Perks like housing allowances and commuting rosters will not be so important then.