Is it beneficial to study for Core 1 and Core 2 together or separately?

I've seen countless people study for both and then take them back-to-back on the same day. That's how I earned all five of mine as well.
Oh, I agree. I took my A+ many moons ago on a dare. I took the 101/102 (yep...that old), on the same day, because some clown decided to dis me for getting my MCSE the week before. When I rolled in with my MCSE and my A+, he had no choice but to shut his mouth.

Felt good doing that.

/r
 
I have taken the A+ three times. I sat for the first in 1998 (Exam 101/102) when it was an adaptive test, on the same day. The 900 series and Core series I took one at a time, the way I prefer. It's a lot of content for someone relatively new, so concentrating on one at a time can be helpful for some.