The options for searching players currently are:
>Search for name
>Search for Coalition
>Search for email
>Search for country
What my suggestion is that when you search for name, you also search for names that have existed in the past.
What I mean goes like this:
Suppose my name is Dog999. I then change my name to Cat111. When you search for "Dog", Cat111 will show up (maybe a little star or something will show up to indicate that the player has changed name) because Cat111 used to be Dog999.