"well manned" is correct and can be used in written English.
You can use it to refer to something that has enough people assigned to it, who are properly trained to perform the task. For example, "The security gate was well manned with trained personnel."
And being well manned, his ship won't sink.
"So the trick with Christmas is to make sure that the stores are well manned, that day-to-day advertising is good, that the merchandise gets into the stores.
Encourage it to jump up to your glove for a tidbit when it's well manned, not as a first step in training.
Bay's spot in left field has been well manned by Kirk Nieuwenhuis, while Mike Baxter has been strong off the bench.
They were well manned at the back, with Brede Hangeland slotting in and Joe Ledley and Mile Jedinak sitting tight in front of the back four.
Adding Olivier Giroud, Danny Welbeck and Theo Walcott into the mix, there is no question that the attack is well manned in terms of numbers and options.
The midfield would be well-manned and the opportunities for team-mates to join lone targetman Dennis Bergkamp grasped when possible.
Inside a well-manned salon, Moore was sporting a baseball cap with the legend 'Made in Canada', a blue hooded tracksuit top, khaki shorts and sandals.
Against a well-manned Watford midfield, Arsenal should also redeploy the central pairing of Francis Coquelin and Mohamed Elneny following their sturdy performance at Tottenham.
When Petruchio's antic charm offensive meets Kate's well-manned defenses, the combustion makes for a lively scene of cutting gibes and scornful retorts that is taken at a galloping clip.
It was attack against a well-manned defence; and it all worked very well for about 30 minutes until the first goal went in – pretty much as it tends to in the domestic competition.
