you need to activate counter types 26 and 27 to show the HO failures for each adjacency. However these types can be activated only for 40 cells at once in 1 BSC.
the default type 180 only shows preparation failure and execution failure. But IMO that’s enough : preparation failure is mostly due to congestion, while execution failure is mostly due to radio failure.
Also, type 26 and 27 give details about the cause of HO (emergency or not), etc.