My thinking behind it is the more I level up , I will go back and do the bits and pieces when I come up against a foe that I cannot defeat.

But you already missed out in the experience, one of the things most new players to Souls games do, is outlevel areas and do it when it is a cake walk, completely robbing themselves of the experience as it was meant to be.

Yeah the summoners make it easier but its more the computer generated one rather than Johnny Level 1023 coming in from Japan with one swipe and the foe is gone.

Doesn't matter, it still makes the boss trival and not a challenge. The jellyfish doesn't do much damage, but makes the boss not pay attentio to you so you can kill it with little risk. It's like watching a movie with ear plugs and blindfold while getting slapped in the face with a cat.

How long did it take you to defeat Margot with no summoners? It took me around 40 deaths with the summoners

It took me about 5-8 the first time, the second time I went about doing it took more like 20. 40 isn't abnormal. He is a very hard boss even for veterns as he is quick, high damage, lots of unique moves, even more unique moves in 2nd phase, lots of hp, he punishes panic rolling, and the slow attacks actually make it harder as you miscalculate frequently.

You will never again have your first experience, every time you go back it will be easier and you can never relive that "first time", doing it with summons and high levels is just robbing you of that experience, it is suppose to be hard.