I'm not a professional at this stuff, but I am a professional engineer. Been hanging around here a while, and I think I understand the issues involved.
It's difficult to make any assurances with an attic installation. Too many variables.
Look at the HBU33 specs here.
http://www.antennacraft.net/Antennas/AntennasHBU.html
The HBU33 has a 85" boom (more than 7' long). The half-power beam width is 56 degrees. This spread is much smaller than the spread between the groups. So no, if you point half-way between, you will probably get few if any stations.
In the attic, you should probably not expect to get WATC and WPXA unless you point right at them with a big antenna. Then you will likely lose most of the stations from the southwest. Sorry, no better solution, unless you move to the roof (or start thinking about much more complicated solutions with multiple antennas).
You MIGHT recieve all the stations you want if you buy the DB8e and point one panel southwest (228) and one panel northwest (324). But I would not bet money on it.
If you had the DB8e, you could try it one of two ways -
1) one panel pointed NW and one panel SW.
2) both panels pointed SW, and forget the channels to the NW.
If you don't get WXIA, you can always add another dedicated VHF-high antenna to try and get it. This could be the Y5713, or the CS5 if you want something more compact. Signals from VHF and UHF antennas can be combined into a single wire inexpensively.
No guarantees on any of this. If you insist on an attic installation, you probably will not get everything you want.