Hmm.. The important question is, do you make use of
Urborg. Lets take a look:
- Colorwise you need way more blue than black, so I don't think its a big deal
- in order to generate value out of the number of swamps, you need (at least at its current state) to draw one specific card: the magus. But the magus doesn't help you unless you got at least 3 out of 10 possible spwamps out, or urbog. The chance until turn 10 (assuming no extra draws) for 3 swamps + the magus (or a tutor to get him) is ~16%, the chance to draw urbog and the magus until turn 10 (taking the tutors into account) is ~27%
- since
urborg works symetrical, it could also support your opponents (if they play black)
All in all,
Urborg is a great land, but if you want to play it, I would reccomend to add more than 1 card to generate value out of it, in order to increase the chance, that you can really make use of it.
Crypt Ghast,
Mutilate,
Nirkana Revenant and (if you want to attack)
Filth could do the job.
Otherwise, better invest the money for other cards.
Urborg isn't that cheap.
Speaking about investing money for some cards, what about
Diabolic Intent? Its a little more affordable than
Diabolic Tutor and the downside that you have to sacrifice a creature shouldn't hurt you that much, at least after the point you've got oona on the board.
And I've got another idea about your control section:
Split Decision. It's a little playgroup dependant, but usually you should be able to deny something important or grap some value. Besides that, I personally like the politics factor.