Sure, in a game of D&D it is possible for a party to be surprised by one player's actions, but more often than not we all know what we want to do as soon as combat goes loud. Having a system for players being ready vs. not ready might be ideal, but I think it would be better to err on the side of party members always being ready for combats that the party initiates. If my whole party sneaks up planning to attack an enemy and my rogue takes a shot, none of us should be surprised that the enemies respond, and we should all get a chance to take a shot or cast a spell as a readied action.
I don't want to derail the thread, as the issue I want to discuss has been thoroughly argued about in a thread that was recently
closed, but it sounds to me like another shortcoming of stealth and how it transitions into encounters. If every nearby companions were included in the combat encounter rather then being added on one by one basis that wouldn't happen - just roll initiative for everyone, stealthed or not, and the problem is solved.
One a side note lack of readied actions has been puzzling - especially as Larian's seem to be very concerned about not allowing players to "waste" any part of action economy it seems like an odd ommision. It's a mechanic that should work really well in cRPG.
