Giant pumpkin plants not so giant :(

[The nut house]

Hi all,
This is my first post here nice to meet you all.

My first post is a question for anyone with experience growing pumpkins. Big pumpkins.
My family and a few others are having a competiion to grow the biggest pumpkin in time for Halloween. Each family was given 4 Dills Atlantic seeds
But it seems like only 1 family has really healthy big pumpkin plants - the others are slow growing and being overtaken by smaller variety o squashes in terms of plant size.
The healthy plants (mine! Yay!) were planted a week later than the others but we all planted indoors and moved them out at the same time ish.

I wonder what could be the key!?