I find that I have difficulty when it comes to placing fingers right under or over each other on the same fret, for example the A major chord.
Is this a problem that everybody has initially, or are my fingers just a tad fat?
I'll post a picture if I can, because I know that fretboard width can play a part (I have a rather narrow-necked acoustic steel-string).

You can cheat on some of those and hold two strings next to each other with one finger.

I mean, whatever is comfortable for you dude.

no that could be due to not enough flexibility in your fingers. Someone i know has chubby fingers and he had the same problem. He worked on a few hand exercises to give him more flexibility, and if you want to use 2 strings that might work better. if you hit an a on the first string you could also hit that same note on the second string as long as the guitar is in tune. Try to go down the 2nd string until you find the same note that you want to hit on the first string.

Nope, chubby fingers, short fingers, long fingers, whatever fingers, they make no change at all. You can still play. just practice more and good will come out of it. You'll struggle with things other have ease with, and vice versa. it's a normal process :p

thats true. Words of advice brought to you in part by Seb.

With the A Chord, you can just use one finger, just learn how to use your finger joint to where you keep that top string open while barring the 3 strings necessary.

Chubby fingers or so to say ( stubby ) does make guitar playing a bit more of a struggle for you, Practice makes perfect! You will get it all in a bit of time " Pull the Strings closer together "

Remember
THANK YOU MR MINOR!!