Spelling Out English Words

(assuming that people who 'don't have accents' are those that are speaking their mother tongue, whereas people that 'do have accent' are those that learnt English later in life, as their second language)

Why are the people with accents are the ones with the larger vocabulary? This is easy to see when spelling out a word. For example: When an English speaker spells out the word 'Car', they say "C as in Cat, A as in Apple, and R as in Rabbit'. Whereas people with accents say "C as in Catastrophe, A as in Administration, and R as in Republic"

One guess is that when people learnt English as their first language, in Grade1, the teachers would use easy words to associate with letters, words that a child can say easily, like 'cat' and 'apple'. Whereas, when someone learns English when they are in Gr6 (or a higher grade) when they already have a better vocabulary, they are taught bigger words to associate with the letters.