The Swans were all at sea and looking down the barrel of a hefty loss at 29 points down in the first term, but fought back to hold a slender lead late in the third quarter before faltering in the final period.
"I thought the whole thing was a real positive. To be able to play Collingwood on Friday night here is outstanding," Longmire said.
"To be able to play Byron Sumner on Andrew Krakouer in the first quarter, Sam Reid at centre half-forward, Lewis Johnston at full-forward - they're all just babies in football terms - against a team that plays like that is outstanding.
"Some of our older players really got a bit of touch … as well.
"They jumped us in that first quarter, but I think we did well in the second and third quarters to get back in the game. Maybe we expended a fair bit of energy [doing that] and probably ran out of legs a little bit in the last quarter because we tried so hard to get back into the game after the first."
After a strong showing in the side's NAB Cup opener, former Hawk Josh Kennedy continued to impress with his 30 possessions, leading all players on the ground and earning the praise of his coach.
"We see him as a really important player in our midfield mix," Longmire said.
"You saw tonight that he's big, he's strong and he's clean most of the time, so we think he's a really important player for us."
Despite the loss, Longmire is happy with his team's preparation for round one of the premiership season against Melbourne.
"We were faced with 10 operations at the end of last season … so from that point of view, it is a bit different from the year before," he said.
"We've made sure that we've got those blokes going as quickly as we can. Fortunately a lot of them have been able to run, so they've got their fitness levels in pretty good nick.
"We've still got time in the next few weeks to get some good game time into them."
The coach rated Shane Mumford, Nick Smith and Daniel Bradshaw as good chances to play their first matches of the pre-season campaign next week with Tadhg Kennelly and Lewis Roberts-Thomson still at least three weeks away.
