The more exact a definition is the better it is. I was referring to how Steve defined "HO" without having words like "shot", "pass", "merge" or like you are using "attack" attached to it. IMO, those add some variety to the definition. What does "attack" mean to you in regard to HO? Does it always include shots fired or is it more like engaging with an intent to shoot?
To Steve,
If you say there can be several merges in an engagement, then you have to define what you consider an engagement

IMO, one needs to disengage to be able to re-enagage with a new merge. I would call that another engagement. Number of engagements does not depend on number of HO possibilities. It is pretty much semiotics, but how can we argue about anythig if words have a different meaning to different people, or if some want to twist the meaning to serve their agendas.