Hi. Im currently training at home with dumbbells.
My problem right now is my side lateral raise and tricep extension is really weak.

Im progressing with heavier load for all other stuff, but those two Im stuck with way lighter weight.
Got progress but really slow.

Is this normal? 
Im trying to solve this by "cheat forms" using heavy weight + control the eccentric movement,
and put more reps and extra set to the light weight.

Is this gonna be good enough?
Sifus please help.