Either you have to start with dense cylinders so you don't have to worry about topology and connecting edges or you would have to pay attention to cylinders sides to avoid triangles (which I think isn't a big issue in this case).
You can move the fin inwards towards other fin, this way you will have room for support loop for outer edge and it will also blend with flat top surface too nicely. Since in game it will get baked down on low poly and no one is zooming in that close to an asset. Another thing in games we are not doing CAD precision.
@perandall not sure what exactly your question is but I suppose you're talking about pinching artifacts caused by uneven spaced loops ? If so enable loop tools addon under blender preference > select the row of edges you wanna space like this > loop tools > space. You can also add an extra softness by using the relax…
Thank you for your answer! No problem at all. This model isn't for bake. Despite this, what do you think about the number of vertical loops? In my opinion, 72 loops for such cylinder is too much, but without them, the shading looks really ugly.