planting spuds

Last year was my first  growing my own veg and I used Hessayon as my reference. As well as this forum.
I spaced the planting of my spuds out, a few weeks between 1st earlies- 2nd earlies and my `Main crop . My confusion comes when some of the old sages on the allotment said " oh no, wack em all in at the same time. My gut feeling is to follow Hessayon as I had a pretty good crop. Thoughts welcome.
 

I plant all mine at one ... but this year I'm going to plant the First Earlies at 2 week intervals for a month.  We like them really small ... and planting them all-at-once meant that the last lot we harvested were already larger than we like.

Mine would go in all at once,  but I can't manage 300 in one day. I just start and then keep going until they're all in.