When AOS was announced I assumed that it would be about Coulson leading a team
There's a team, and he's leading them.
Check.
Even ignoring the "highest marks since Romanov" comment, Ward is a pretty highly skilled operative in a lot of fighty-type things.
And May is the legendary cavalry who can use the knife you just planted in her shoulder to cut herself down and take out you and your goons. She is also able to pull a 180 in cargo plane, and fly it into the eye of a superstorm.
And as a team, they were able to out-perform
all of Hand's other teams, in finding and rescuing Coulson. And were also successful in taking on a mission without an exfiltration plan, just like Barton and Romanov.
Check.
IIRC, FitzSimmons were the youngest academy graduates. They have been shown doing quite brilliant things, like curing an alien electro-virus, building back-scatter X-Ray glasses, and miniaturizing the night-night pistol.
Check.
as they responded to the weird and wonderful things that were suddenly cropping up on the MCU's version of Earth.
Like, say, HYDRA lasers, Gravitonium bombs, Ice storm machines, teleporting dead people, alien electro viruses, and extremis armies.
Check and checkmate.