The Dragons initially aimed to have unveiled Anthony Griffin's permanent successor by now but were forced to change tack when front-runner Jason Ryles knocked them back last week.
Premiership-winning ex-Dragons and current NRL assistants Dean Young and Ben Hornby remain on the shortlist, as does Flanagan, who met with the club on Wednesday.
Having guided Cronulla to their sole premiership victory in 2016, Flanagan is the only one with head-coaching experience which has benefited Seibold since the pair joined Manly this year.
"Any coaching staff that has an ex-head coach on staff, I think that's a really positive thing because they've been through the furnace," Seibold said.
"From my understanding it was a really positive conversation that they had (on Wednesday).
"He feels as though there'll be a resolution sooner rather than later.
"I hope he gets the job. I think he's qualified to get the job."
But Bennett believed the Dragons needed to commit to rebuilding around a younger coach.
Bennett led the Dragons to the 2010 premiership and after leaving a year later, the club sacked three other coaches - Steve Price, Paul McGregor and Anthony Griffin - in the pursuit of an elusive second title.
Young and the incumbent Ryan Carr have also held the job in an interim capacity but in the 11 seasons since Bennett's departure, the club has played finals only twice.
"Changing your coach every week doesn't help," Bennett said.
"They've got to go long-term, you can't keep changing coaches and think you're going to have a successful club.
"I'd be going for a younger coach, someone they have to put their faith and trust in and make sure he gets the support he needs."
Bennett holds both North Queensland assistant Young and South Sydney's Hornby in high regard, having coached them on the Dragons' run to premiership glory.
"They're wonderful men," he said.
"Ben had three or four years at South Sydney and has done a great job. Dean's been up to North Queensland and done a great job.
"They've got the DNA in their blood, they've coached lower grades there."
Time is of the essence for the Dragons, who are keen for their new coach to begin working on roster management as soon as possible.
The Saints have struggled in recent years to attract elite talent and have faced speculation captain Ben Hunt could agitate for a release now that close confidant Griffin has been axed.
A major advantage to appointing Ryles would have been the Sydney Roosters were keen to release him mid-season, allowing him to devote full attention to the Dragons.
Traditionally, assistant coaches are not given that luxury and Seibold is yet to determine whether Flanagan would be permitted to leave early if offered the Dragons job.
Sitting outside the top eight in the crucial State of Origin period, Manly cannot afford distractions as they plot a return to the finals.
"It's something we'd need to put a little bit of thought into," Seibold said.
"(But) there's no point thinking about it until Flanno gets an offer and he wants to go.
"If he does then we'll put some things in place to make sure there's the least amount of disruption possible."
