Ah, didn't see.
Ok, simply, there's too much going on and too little EQing work, from what I can hear. If you cut out all the lows from your string parts and layer in a really soft sub, it would sit a lot better. Strings are a texture, and when applied to EDM, they have a completely different set of rules.
When working on a string arrangement, it's important to utilize all ranges of the instruments, where cellos and basses can reach the lowest end of the violas, you can pull everything up and leave the low end out of the composition until you want that impact, or for full orchestral compositions, you can fill that space with brass or large percussion.
In EDM production, you've got that digital edge, you can lift out that low end, keep the texture and replace it with something synthetic and end up with a clean mix. The same rules still apply though, if not more so. If you have too much in the same range and you limit that frequency range it can be heard in, you'll end up with a bubble of midrange in your mix, and end up scratching your head. I've been there.

As for the rest of the orchestra, it's how you layer it, what you swap out. The orchestra is huge, and knowledge of orchestration is pretty much a must, to some degree, maybe not entirely from a classically trained point of view. Knowing what combinations of instruments works well, the different common textures, making sure that the instruments breathe organically, wind players don't have infinite lung capacity, string players don't have infinite bows, and paying attention to those small details adds a lot of life and realism to your tracks, and can also help save your mix, too, if you know what you're doing.
Make sure you add reverb and delay to the strings. Basically for EDM, you need to take the strings out of place from the concert hall and into your track's sound space.
No, no, no. x_x A lot of string samples have their own natural reverb, and for those that don't, when you're working on EDM, where the mixes need to be tight, and adding reverb and delay haphazardly, especially to something such as strings will just add unnecessary gain to the signal. If you're working with staccato string lines, delay can work if you're very careful with how you EQ it into the mix.