The idea isn't complicated. The four-star XYZ cards are interchangeable and easy to summon, if you pull the seventh on turn one number 99 will mitigate the poo of that, he also makes it easier for that occasional cxyz. There are too many great rank 8s, I like these. I don't much care for bringing out Cyber Dragon, so It isn't in here. It's a great card tho. Anyway, galaxy soldier is purely a search, it can be used as fodder for the single link card or be fodder for Hyper Galaxy etc combos expedition. The link card is great support all around, Gives you a card and whatnot, advances plays, disrupts etc. But the xyzs are better, that's why I only have 1.
Numeral hunter is disgusting and works well in this deck for one reason: occasionally your broken galaxy xyz gets stolen. Or maybe someone brings out something like Zexel.
Anyway, it's simple. Have fun.