With the jumpers properly seated, it doesn’t really matter which row... but considering tweeters are much more limited in their power handling capabilities, I usually stick with plugging into the Low side just in case.
You are using them with subs, so I would set to small and cross over between 60 and 80.
My speakers which reach down to 25hz are crossed at 80 because I get better clarity from the mids and highs there than if I cross lower.
Remember, the xo is not a hard cut, but a gentle slope, so your speakers are still reproducing below.