Why the gate is a perfect storm
A front gate concentrates everything a sociable or territorial dog finds exciting: unfamiliar voices, keys and latches, your own raised energy, and now — the new twist in your question — other dogs arriving on the far side of a barrier. Barrier excitement builds fast because he can see and smell the visitors but cannot complete a normal greeting, so barking, spinning, and lunging fill the gap. Asking him to simply come away in that moment, untrained, is asking for the finished behavior without ever teaching its parts. The parts are: notice arrivals, turn away from the gate on cue, and settle into an alternative job nearby.
Rehearse with a borrowed, boring visitor
Set up practice when no real visit is expected. A friend with a steady, older dog stands well beyond the gate, doing nothing interesting, while your dog is on a lead inside at a distance where he notices but can still eat and think. Call him away from merely looking toward the gate, reward generously when he turns to you, and let him glance again — looking is allowed; losing his head is what you are training around. Across sessions, close the distance in small increments and let the helper approach the gate itself, always quitting while he is still succeeding.
Give the arrival a script everyone follows
Real visits fail when three people shout three different things over barking. Write the script down: one person takes the lead and works the practiced recall, one greets the human visitors, and the visiting dogs stay outside or enter one at a time, calmly, rather than flooding through together. Your dog's job after coming away is concrete — a mat just inside the door, a stuffed food toy, or a settle in the next room with a chew — not a vague instruction to calm down. If he cannot settle, he was too close to the action; move his station further back next time instead of repeating a failing setup.
Manage the days training is not enough
Some arrivals will outrun his current skill: a boisterous young visiting dog, children racing in, a delivery at the same moment. On those days, management is not defeat — put him behind a baby gate or in his settle room before the latch lifts, with his chew already there, so he never practices the frantic version. Every frantic rehearsal at the real gate strengthens exactly the behavior you are trying to retire. Protect the training by controlling how often he faces the full-strength version, and increase the challenge only as his staged successes stack up.
Make the plan visible to the whole household
Gate manners collapse when one family member lets him charge out to say hello because it feels friendly. The routine only holds if everyone runs the same script: same cue, same mat, same rule that visiting dogs enter one at a time. Rotating who plays the lead-handler role in practice also stops him from listening to only one voice in a noisy hallway. Recording those practice jobs and visit-day roles in KinsLe Care Teams means each person can see the agreed gate routine and confirm their part was done, instead of improvising at the worst possible moment.