First grafting was poor. Common mistakes??

I should say the bees were not in the right mood, plus they might have some kind of virus problems.

Usual size of a starter, in literature, is 3 kg (of bees), you can put it in 5 frame box if it has enough ventilation holes and is about 5 cm higher than the frames you use, put in shade of cellar. It is too big for a hobbyist.

If you wish to use 5 frame box, here is my recepy:
- take 3 frames from honeybox full of bees
- shake the bees of 3 open brood frames (no queen!), use brush if there is a flow
- put in one pollen frame, sprinkle some water on it

wait 4 hours

make the grafts

put the transfered larvae in the middle of the box and the pollen frame nex to it

max 15 larvae (one frame with Nicot system)

one cell builder can take care of these, but no more

I used a method layer out in a book by Kelley in which he suggested using a strong colony with the Queen below an excluder. There were a lot of nurse bees and I shook another frame in as well. I still suspect not enough nurse bees for finishing because there was a very good start to the cells.
When a colony is understaffed with nurse bees do they do a poor job and raise malnourished bees across the entire grafting or do they make some duds and some good ones? I don't claim to know anything about this but I'm wondering if the cells are not provisioned with enough food will the pupae simply not have to sustain itself and die? I'm also wondering if the small size indicates the pupae has not gone through all the instars/sheds?
The method I'll try next uses a queenless starter aka swarm box. I've read this can be done as mentioned above by building it a few hours prior to grafting and putting it in a dark place or building a day before grafting. I know this time I'll have enough nurse bees.
The book I'm following for this next attempt States that a strong finisher will finish 45 cells so that's how many I'm going to try. I'm going to combine the starting bees with the finishing colony so they will have whatever bees that started the cells as well as the nurse bees from the finishing colony. Would it be OK to put the cells on top of a honey super?
I know this variation isn't good for commercial rearing but for me it seems easy to just take the starter colony box and plop it on top of a finisher.
I am also going to do 15 cells using the cell punch method. Maybe this will tell me if my grafting technique is out now whack. I did choose larvae that were sitting next to eggs when I grafted but I'm far from being proficient at picking them up and placing them in the cells. I have a magnification visor/light coming in the mail which will help. I'll also try some other grafting tools and discard any larvae I think may have touched the cell wall during pick up or deposit.
Thanks