they could have but given how bug the gates of Justice are they would have lost em.. plus they could have followed with ships but Aokiji stopped then coz the fleet was wrecked..
this arc also shows us Luffy as a pirate was more of threat.. and they wanted to annihilate the crew with him.. but post Enies Lobby the command to kuma was "bring Strawhats head back"
Except there was a time window when they (= the Vice Admirals) would have been able to capture Luffy without any issue : between Lucci's defeat (Luffy was half dead in the tower) and before the Strawhats escaped (and before Aokiji gave the orders to give up).
In this time frame, they had plenty of time to do something.
Heck, they could even have intervened in the Luffy-Lucci fight to increase the chances to capture Luffy.
But they did nothing except watching...
Regarding the crew, Captains and Lieutenants were already taking care of them. So the Vice Admirals had widely the luxury of focusing on Luffy.