Ulrik wrote:
Out of curiosity, what were the flaws?
It's effectively an automatic Engage action, regardless of Initiative roll. Once you are in Engage range, it's impossible to fail to Engage. It allows sure-fire combination actions, i.e. you can always successfully retain/Engage, regardless of Initiative value or mods. Assault-oriented Teleporters become impossible to fail with (as long as they have a chance to activate).
Also, an Engage action doesn't require the player to actually initiate an assault. If they just move away, then an assault never starts. That's arguably no different than choosing to move on a Hold action, but you can end up with odd effects like Infiltrator units taking a double move.
If the only concern were game balance, then most likely all of that could be dealt with via point costs, but the effects are "gamey" or generally undesirable to many people.