Here's a drill that always moving and will highlight the players that are in shape vs. those who have work to do, while at the same time exercising critical baseball skills. I've used it for all ages and a ten minute round of this is good to interject from time to time.
Player at plate (P3) (no catcher gear), player at 2B bag (P2), player at 2B deep playing position (P1), rest of players lined up behind 1B. Coach (C1) with Fungo on right side of infield, coach (C2) (or mature players) at first.
C1 fungoes ground ball to P1 at 2nd base playing position. P1 makes play to C2 at first, then runs toward C2 to within about 10 feet and makes button hook out to RF position to receive an over the shoulder throw of the same ball from C2.
C2 should keep an extra ball in back pocket (or nearby if players are executing the C2 toss) for wayward throws to keep it moving.
Sprinting to RF, P1 receives catch over his shoulder from C2, or shags it if missed, sets himself and throws to P2 at second.
P1 then sprints to second to become P2.
Once C2 has made over the shoulder throw to P1, new player sprints out to take 2B position and becomes the new P1. C1 maintains the flow of the drill by fungoing once the previous P1 has made his throw to P2.
P2 (at second) makes tag on throw from P1 OF, sets himself, and throws to P3 (home) then sprints to home to become P3.
(if you want to provide a little extra time between sprints you could have more than one player start at P2 and P3, and form a mini line at those spots as well.)
P3 makes tag, and brings ball to C1 bucket while sprinting to end of line of players waiting behind first.
Throwing and sprinting are going on simultaneously with hits from C1 to P1.
The entire team experiences wind sprints, ground ballwork, over the shoulder pop fly work, OF to IF throwing, IF to Home throwing, and tag work all in one drill.
Run it as long as it takes to get them winded or make it a competition until they execute X number of perfect reps.
(while in line these players are basically catching their breath before their place in the rotation begins again. That line presents opportunities for added drill work, perhaps with a third coach (or mature players) throwing Bunt work)