No, it won't always over-ride it, but that's true of all dogs, not just sighthounds. As I said before, the difference with sighthounds is the increased likelihood they may catch what they're chasing and the potential for them to be miles away in seconds, simply because of the speed at which they can cover ground.
No-one can ever say their dog has 100% recall, simply because dogs have a mind of their own and sometimes choose to use it at the most inopportune moments. It doesn't mean they can't be let off lead, just that they can't be let off lead everywhere.
I was just wondering if you are getting negative responses from rescues because you sound like you are essentially asking for the perfect dog, ie doesn't want much exercise, always come back when called and great with children. The vast majority of people approaching rescues also want those qualities, when the reality is that only a small percentage of rescue dogs will come 'ready made' and most will need at least some basic or remedial training.
I'm not saying this is you, because as you've already said you are willing to put the work into training, but rescues do get a lot of calls from people that want dogs that will just slot right into their lives, be calm and obedient, not want much exercise and always come back when called. This really isn't a very realistic view of taking on a rescue - or any dog and they may get short shrift from those at the sharp end of dog rescue. It could be that you've been wrongly classed as one of 'those' enquirers in error.
If not - and they have discussed it thoroughly with you, it could just be that they've no dogs in just at the moment that would be a good match for you, but new dogs will be coming in all the time and the best way to keep up with the latest arrivals is to frequent their FB pages, rather than just the websites.
To be honest, the best rescues are the ones that honestly say they have nothing suitable for your circumstances, rather than rehoming an unsuitable dog with you, only to have the adoption go awry. Most rescues don't have the resources to follow people up and call them when a good match does come in, so you're best off keeping an eye on FB and enquiring/applying if you see a dog you think may suit. Some rescues may prefer to arrange a homecheck in advance too, then if a suitable dog comes in the adoption can go through more quickly.