personally i like to think about enneagram/MBTI correlations, cause i think those have a big impact. an ENTP 7 and ENFP 7 are going to look a lot alike, much more so than an ENFP 4 and an ENTP 7.
i think usually you can see correlations like 1w9 looks more like T and J, 1w2 more like F and J, 2 more like E and F, 3 more like E and T, 4 more like I and F, 5 more like I and T, 6 more T and J, 7 more E, S, and P, 8 more E, T, and J, 9 more S, F, and P.
my thoughts on lookalikes, mostly based on experience... (and a little guesswork ;] )
* = prettyyy unlikely combo, lol
INFP 1, 2 -> INFJ
INFP 3 -> ENFJ
INFP 4w3, 7* -> ENFP
INFP 4w5, 5 -> INTP
INFP 6 -> INTP, INFJ
INFP* 8 -> ESTJ
INFP 9 -> ISFP
ENFP 1 -> ESTJ
ENFP 2, 6 -> ENFJ
ENFP 3, 6, 7, 8 -> ENTP
ENFP 4, 5*, 9 -> INFP
INFJ 1w9, 8* -> INTJ
INFJ 1w2, 2w1 -> ISFJ
INFJ 2w3, 3, 4w3 -> ENFJ
INFJ 4w5, 9 -> INFP
INFJ 5, 6 -> INTP
INFJ 7* -> ISTP
ENFJ 1 -> INFJ
ENFJ 2 -> ESFJ
ENFJ 3, 8 -> ENTJ
ENFJ 4w3 -> ENFP, INFJ
ENFJ 4w5, 5, 6 -> INFJ
ENFJ 7*, 9* -> ENFP
INTP 1, 5w6, 6, 8 -> INTJ
INTP 2* -> INFJ, ISFJ
INTP 3 -> ENTP, INTJ
INTP 4 -> INFP, INFJ
INTP 5w4 = most INTPy INTPs

INTP 7* -> ISTP
INTP 9 -> INFP
ENTP 1, 3, 8 -> ENTJ
ENTP 2* -> ENFP, ENFJ
ENTP 4* -> ENFP
ENTP 5, 6, 9* -> INTP
ENTP 7 -> ESTP
INTJ 1, 6 -> ISTJ
INTJ 2, 4, 9 -> INFP, INFJ
INTJ 3, 8 -> ENTJ
INTJ 5, 7* -> INTP
ENTJ 1, 3 -> ESTJ
ENTJ 2*, 4* -> ENFJ
ENTJ 5, 6 -> INTJ
ENTJ 7, 8, 9 -> ENTP
ISFP 1, 2, 3* -> ISFJ
ISFP 4, 9w1 -> INFP
ISFP 5, 6, 9w8 -> ISTP
ISFP 7, 8 -> ISTP, ESFP
ESFP 1*, 2, 3* -> ESFJ
ESFP 4 -> ENFP
ESFP 5*, 7, 8 -> ISTP
ESFP 9 -> ISFP, ENFP
ISFJ 1w9, 8* -> ISTJ
ISFJ 1w2, 2, 3 -> ESFJ
ISFJ 4* -> INFJ
ISFJ 5, 6 -> INTP
ISFJ 7*, 9 -> ISFP
ESFJ 1 -> ISFJ
ESFJ 2, 6 -> ENFJ
ESFJ 3, 5*, 8 -> ESTJ
ESFJ 4*, 7, 9* -> ESFP
ISTP 1, 3 -> ISTJ
ISTP 2*, 4*, 9 -> ISFP
ISTP 5 -> INTP
ISTP 6 -> INTP, ESTP
ISTP 7, 8 -> ESTP
ESTP 1, 3, 8 -> ESTJ
ESTP 2*, 4*, 9* -> ESFP
ESTP 5, 6, 7 -> ISTP
ISTJ 1 -> ISFJ, INTJ
ISTJ 2, 4* -> ISFJ
ISTJ 3* -> INTJ, ESTJ
ISTJ 5, 6 -> ISTP, INTJ
ISTJ 7, 9 -> ISTP
ISTJ 8 -> ISTP, ESTJ
ESTJ 1, 5, 6 -> ISTJ
ESTJ 2 -> ESFJ
ESTJ 3, 8 -> ENTJ
ESTJ 4*, 9* -> INFP
ESTJ 7 -> ESTP
whew