If space were not a luxury then most would organize by era, manufacturer, or theme. Also most of us are used to seeing pins in rows so in your mind that looks “correct”. Nothing wrong with putting them on an angle if it works for your space. It doesn’t really matter. Since space is a luxury and most of us only have so much most maximize the space available. The key is to not make them so crammed it’s uncomfortable to play or people are on top of each other. The other consideration is access to pull the glass for small fixes…nothing worse than having to move a game to get the glass off. Also if you move games in and out frequently is something to consider….nothing worse than having to move multiple games to access one.