I have found that frogs can be pretty tuff to get to the boat. This is my 2nd year using them. My first year i probably only caught 15% of them and this year somewhere around 80%. I was using 17lb mono with a MHF rod and i believe i wasnt hook setting correctly.
This year i bought a better frog setup. I have 50lb braid and a 7ft 3in heavy rod and i added a lake fork trailer hook to my frogs if i could. I worked on my hook set by when i saw them hit it i would lower my rod to around 4 o'clock, reel in all my slack to where i could barely feel the bass on the line, then swing for the fences.
Im not sure if its the setup or my hook set or both but im doing much better. During the first year i was almost ready to give up with them but i didnt because there are so many people that do well frogging. Watch some videos and keep working with em, you will get better.
Also i have caught some pretty small ones with a frog. I literally made one skip 8 feet during a hookset and ripped a good size hole in his mouth.