The problem is none of the scores are going to be identical (differences between the data and the individual implementation for the bureau if we're talking FICO) and not all of those scores are FICO anyway.
Lenders can pull any score that FICO and others offer including internal scores individual to them; personally though I don't really think any non-FICO and *possibly* Vantage scores are worth tracking at all; the score from TU is at best Vantage and worse educational, the EQ one may be FICO or it may be educational depending which you got, and the EX one could be either too... they peddle both.
Credit Karma is explicitly Vantage 3.0 currently.
TBH: the whole affair is a little suboptimial from our perspective as consumers, I personally just pick a benchmark score and go over time with that but even that isn't entirely accurate - my tracking score has always been Equifax Beacon 5.0, one of the scores on the mortgage trifecta, and even with that it was 25 points below my actual mortgage mid-score. Admittedly happy, HAPPY! surprise, but even with all I know and all the scores I track, it was still something of a shock.
On the plus side I knew that before I applied as a result of the 3B instant-in-time pull here, I really can't say enough good things about that particular MF one when it comes to doing anything important credit wise (mortgage, maybe auto loan, rest doesn't rate in my world).
