Ow another thing.
I trained gsd with commands and it woked great,
Co's diffrent story.
You need to be more physical for an early stage to prevent body power games.
I am not that big and will always loose the power/weight games so to prevent that i use my body from they one.
For example: ahh he is so cute he is standing/hanging pushing my body well even such a small puppie is looking how far he can go.
So i lift my knee firm suddenly against his chest so he eed to step a side. I dont say a thing but i claim my space with my bodylanguage.
Be firm with your bodylanguage and dont use too much words. Its very importend to do that when they are very young.
Same when to jump on you, i lift my knee very firm with no words, he will understand very soon that you dont want that.
I have seen major differences between the co and gsd and developed a total diffrent way to raise them.
They need to earn your attention and dont take it for granted when they learn that very young they are way more easy to raise.