You'll likely find that the video is about 8 years out of date.

To see what works for base defense, & what doesn't, watch base hits, including your own via replay. I've personally found replay accuate enough to make adjustments where needed.

Your base works hand in hand with your guard. You can't rely on just one or the other to defend your base, guard placement is very important.

I'd recommend finding a good alliance that can teach you the ropes, BEGNR is probably your best 1st port of call.