It really depends, mono sents can make it in ELO if you can dodge SOA all day (SOB is not as big a problem for sents as it is for, say, montanas), half-deck sents without Lehane suffer pretty badly though.
For reference, my mono sentinel build which I was able to take all the way to 1306 after falling from 1380 to 1187 is:
That was pretty much what I was thinking minus Tobbie.
Tobbie is pretty iffy, but we don't have Lehane and I don't like Aurelia due to pretty low damage, so..
Tobbie can be quite menacing too, in a fight without SOA present.
Again, if you can dodge SOA all day, 9-powered goons can take it till the cows come home.
Honestly tobbie is way way way way way way better than rick. never ever thought of using rick the moment tobbie was creatde.
Why no Lehane she isn't ELO banned, and I can't think of a single reason to not use her in any sentinel deck, ever.
@aravan look at the date when the guy posted the deck.
I'm using a sentinal half deck combined with Geist. It's working Ok so far, but I'm kinda a newb, so I don't know if it could be improved. It has some room, but I'm strapped for clintz.
Add: Lehane, Miranda
Minus: Katja, Tessa