That's quite a good base collection. You've already gotten the Sebenzas out of the way (it'll be mostly downhill $$-wise from here), you haven't fixated on any one brand, and you're keeping your blade profiles and lengths diverse. This is the type of collection I strive for too. But there are a lot of ways one can go.
A Strider would be a good next one. Just food for thought--it looks like you could use some kind of more dedicated 'outdoor' folder, such as the HEST 2.0's or similar. I'd also say you are ready to acquire an Emerson

.....and at some point in time a fixed blade or two, again maybe a shorter one and a longer one, but you have plenty of time to study those.
Yours is one of the best base collection starts I've seen insofar as my own tastes are concerned. Others will point out different things though. You have to remember it's pretty much all in personal taste and opinion.
The other thing I can tell you is to stick around here at BladeForums if you want the best on knives. Learn about what constitutes knife-abuse, proper sharpening/stropping,
correct care and ancillary knife products. So many of these people are amazing in their knowledge....
My recs for your first fixed blade would be a
Gryphon M-10 or
Hoffner Hand Spear for starters. Also the
original HEST fixed blade by Rowen is a very handy one as well.