create unique but friendly username

is there a way to create unique but friendly username , example:

there are 3 name:

steven seagel
steven russel
steven krud

i wanna create 3 username from these name which is easy to remember but not too long.

anyone can help me?

last name 1st initial i say.... so

seagals
russels
kruds

i dunno theres lots of ways maybe even more unique you could do the first 3 letters of the 1st name and 1st 3 of the last name

stesea
sterus
stekru


but those names have no real meaning so the users themselves prolly dislike them