Shall I give my thoughts or is it irrelevant? @VanGoSunflowers 🤔
I know it's kind of different for me with a guarding breed; the focus with gundog breeds is always on off-lead work. But on the other hand, Pablo is clearly going to be significantly bigger, heavier and stronger than a WCS, so close lead walking without him dragging you all over the place is going to be pretty vital. It's also important if your son is going to have any chance of walking him a couple of years from now.
As you know, my girl is a complete demon on the fields, but with short lead walking she's an angel. She trots along beautifully with a loose lead. It's always been our main focus, because we live at the top end of a moorland village, so to get down to the nature reserve/meadow/woodland involves a fair bit of pavement. I have to be able to negotiate the hill without the dog pulling off my feet.
Because of the vaccines, we didn't get Brie out until 14 weeks, by which time she was larger than an adult cocker. Initially I had her on a harness, which goes against all the breeders/vets/trainers advice for dogs of this size. This is one area where lovely @Bupster and I don't quite see eye to eye. For me, although I tried with both Algy & Brie, a harness does not give enough control, she had too much strength in her chest and I couldn't steer her in the right direction. I persevered for weeks with different types of harness and lead combinations, double ended training leads etc. But she was all over the place and not walking nicely. Almost as soon as I switched to collar only, things improved. I use two different EzyDog collars (double up and check mate) with a 6 foot webbing lead. This is what works for me, but we're all different and our dogs are different.
Again, this, like crating, is maybe an area where large size is an advantage. With a dog whose neck and head is level with your hip, a collar allows very close control when needed. I realise Pablo won't be that tall but it still may be worth trialling a collar for road walks just to see how you get on, even if you still use a harness for long line/ off lead training.
The only commands I use for close lead walking are "wait" and "slowly". I use wait at junctions but I don't use sit while walking, because of their size; their huge bum and long tail can block half the pavement, so nicely standing to wait is preferable. She's not much of a puller, but "slowly" said low and slow is useful for moments of eagerness.
Sorry for the essay, it might not be helpful at all. But, as Landsharks and I always say to each other, with the larger breeds a lot of everyday stuff is different, so some of this might be of interest if another big pup turns up on the thread at any point.