Who is Tuth and why is he worth so much XP?

I've always wondered why Tuth was worth so much XP (4,000) during the battle with Rieltar - even Rieltar himself isn't worth nearly that much.

I just did a google search for "Baldur's Gate Tuth," and this FR wiki entry came up:

http://forgottenrealms.wikia.com/wiki/Tuth

Is this supposed to be the same character? It mentions him being around in the year 1370, which is a year or two after the events in BG1 IIRC.