I usually go for spiders when it is a good option, and I was thinking that when you go for spiders (at least when I do) you often skip the raider phase, because spider is the only factory that doesn't have a raider (besides airplanes but nobody does airplanes as their first factory, and strider doesn't have a raider either, but that doesn't count, as it isn't free at the beginning). You could use flea, but it dies to literally everything, and works a lot better as a scout, which is what I use it for. You could also use venom, but venom is a lot slower than all the other raiders and acts more as a riot as it deals with raiders a lot more effectively, which basically makes the other person stop going for raiders, which means that the raider phase is usually skipped when someone goes for spiders.
As I usually go for Spiders, I usually miss the raider phase, and I was thinking that the Spider factory could use a raider. You might think that a raider combined with venom and flea might be a little too much, but there are other factories that have that variety, such as Rovers, which have dart as well as scorcher, or Shieldbots, which have dirtbag as well as bandit, or even Gunship, which has blastwing, gnat, and locust. So it wouldn't be so unusual for Spider to have a scout, a riot raider, and a raider.
It seems like Spider's strength is stunning units, and then killing them, (kind of like spiders in real life) but maybe I am wrong, I don't know. But if that is the case, maybe the raider would do some sort of disabling (since stun might be a little overpowered?), or slow?, if it had slow, then it might allow some other units of yours to catch up and have a chance to kill it, but slow for a raider might be a little overpowered, but maybe not, considering rovers have dart, which does a decent bit of slow damage and regular damage, and maybe even stun would work, as there is gnat, which is not really a raider but it does do a bit of stun damage, but no regular damage.
Also I think that it might make Spiders more fun to use, as I think that the raider phase is fun (as is everything else), and adds variety of phases, and it is fun to use light and fast units (at least it is for me), you could use flea, which is fun sometimes, but only when the enemy is not prepared, as if they are, they will most certainly die very quickly.
What does everyone think?