Multiple broad-range antennas are not recommended. Even without the line length issue, there's the issue of merging a bad ghosty version of a channel from one antenna (the off angle one) with a good clean channel from the second antenna (the on-angle one) and turning what was good reception into bad reception.

Multiple antennas are only useful when you get specific antennas to receive a specific channel and then use filters to merge the signals. For example with one antenna to pick up 38, you then filter out everything but 38 on that antenna, then filter out nothing but 38 on the other antenna(s), and finally merge the two signals together. But not only are the filters very expensive, but this only works one channel at a time... so if you need 7 channels from location A and 8 channels from location B, it becomes extremely expensive and is the kind of setup only a cable company would have.

Instead - just buy a rotor!