Another "don't overthink it" here. My first grey was picked out for me by the adoption group based on my lifestyle. I first laid eyes on her when she was brought to my house as a foster-to-adopt. Was there an instant connection? No. Partly because she was a very shy, timid dog that had been through a lot of upheaval in a short time. However, in the five years she was with me, she learned to trust me, and became such a huge part of my life, and heart, that when she passed, I didn't think I would ever stop crying. My second grey was the complete opposite of what I was looking for, but it was love at first sight for both of us He has been a challenge over the years (I call him Issue Boy) but I wouldn't trade a second with him.
I guess my point is, the bond will form, whether it is instant, or develops over time.
Oh, and if you meet some dogs that aren't really interested in you, and you feel no strong connection with them, don't worry about it, it happens, but that dog is probably not the right one for you.