The visitors gave places to ex-Yorkshire batter Jonny Tattersall and former Somerset seamer Josh Davey, who had both previously played on one-match loans, while Glamorgan stuck with the team that finished at Trent Bridge since all-rounder Ben Kellaway remains out with a hip injury.
Although Glamorgan chose to bat in sunny conditions, they struggled to get going against Holland who found plenty of movement.
Eddie Byrom (1) edged behind in the second over and Zain Ul Hassan (7) went the same way, trying to leave the ball, as the metronomic Holland’s first eight overs earned him figures of two for seven.
Glamorgan seemed to be recovering only for Hull to strike twice, bowling Asa Tribe for 24 with a fine ball then getting rid of Colin Ingram for 26 the ball before lunch as the veteran South African edged a four, pulled a boundary and then dragged a ball on from off-stump.
If Leicestershire had dominated the first session, Glamorgan struck back in style as Carlson and Dickson put together a fluent start of 126, with Carlson’s run-out dismissal the only flaw of the home side’s afternoon as Dickson hit his stride following a shaky start to the campaign.
Carlson struck 13 boundaries with his usual positive intent and good timing, and although the one that took him to 50 was an inside edge, would have been good value for three figures.
But Carlson advanced to Kiwi spinner Ajaz Patel and flicked the ball to Jake Weatherald at short backward square only for the Aussie to make a smart return for Ben Cox to whip off the bails.
Left-armer Patel was getting some turn and got some bounce to have Chris Cooke caught behind for 12 with the innings back in the balance at 237-6.
Dickson gained in confidence with the occasional flash of aggression, striking 12 fours, but Ben Green had him caught behind after a valuable knock for himself and his team.
There was a late revival from the lower order in the evening sunshine, with Mason Crane timing his shots sweetly at times to reach 48 not out while the stoic Timm van der Gugten defended solidly in his unbeaten 22.
