How to Add a delay between each device to join local server?

Pasted the code you have provided in the link above to all the nodemcu’s with diff auth tokens and powered it up and out of 7 nodemcu’s 4 connected and rest did not even come to life. and also jammed the wifi signal. So later i connected 3 nodemcu’s to one power supply and 4 to the other one. And powered up and now everything connects with a delay(can say this by seeing the led blinking on each nodemcu at diff intervals…even though powered at the same time.)

I guess there is some noise introduced in the circuit and as the vcc and gnd is common for all the nodemcu’s, i guess this problem was arising !!! But the end result will have all the nodemcu their own power supply !! But what do you think the problem was ? Was it purely code related of even power problem ?