Thanks all. It was this sentence that made it so muddy for me:
"Attack Values are divided into ATTACK and MAGIC ATTACK. Each type of attack value is calculated separately."
The example immediately afterward even shows an attack with magic attack and regular attack but it never tells you a TOTAL. It just tells you that you must subtract the disease from one or the other. Very frustrating rule book.
Note that when you halve attack or magic attack, it's one or the other after they're individually summed. So if you have to halve magic attack and your (physical) attack was 7 while magic attack was 5, then the 5 would get rounded down to 2, for a total attack of 7 + 2 = 9