Welcome to rotational grazing! It is amazing what the system can produce once you get the  hang of it. Your title doesn't really have one concrete answer. You need to find that out for yourself and your soils,climate and forages.

First off, leaving your herd in the first paddock for two weeks is way too long. This is important because after grass has been chewed down, in a humid climate like yours it starts regrowing, sending out new shoots.  This time of year that can happen after 5 or 6 days.Think about how fast your lawn is growing.

Cattle left in too long then go back and eat this new growth and will eat everything down too close to the ground and the pasture will take much longer to recover for another round. I suspect that's happened to your first paddock if they were in there for two weeks. That's why it looks like it does.

You need to add cross wires and reduce the size of each paddock open to them at any one time.  This takes a bit of experimentation but ideally put them in a paddock when the forage is about 10" high and move them when they have eaten it down to about 4". This leaves enough leaf area for the plant to fully recover in about 30 days, assuming moisture is available.

With spring pairs, a cow eats a lot to feed herself and nurse a growing calf who isn't really grazing much on his own yet.

Size your paddocks with moveable cross wires and step-in posts. Start small, even one or two acres at a time, check them daily and see how long it takes them to eat whatever area you have open down to about 4".

You will see how much area they need for, say 3 days, to go from 10" to 4". And that's the size of paddock you should give them every 3 days.  Try not let let them graze back on grass they've already grazed more than about 7 days ago. I don't like using a back wire so I just move a lead wire ahead and switch paddocks  completely about once a week.  If you keep good grass ahead of them they won't generally go back on the grazed new shoots.

This system will give you the best grass utilization and max carrying capacity. But it needs to be 30 days before they go back to the first  paddock. If you do 3 day rotations and can't keep them away from the first paddock then you have to consider maybe 25 pairs are too many for your soils and climate.

Some fertilizer may help the first paddock catch back up but once you get in a rhythm you shouldn't need fertilizer.

One obvious issue is reducing paddock size but still keeping access to water, salt block and mineral. You may need to be creative this first year.

Best of luck.

ETA: This reminds me of how non-cattle people seem to always ask "How many cows do you have?"

My stock answer is: "Sometimes too many, and sometimes not enough"  The right number for any pasture and climate and soils is sort of a moving target. We just need to get close. And don't be afraid to put out some bales of hay rather than let your pastures get eaten down too low.