Took a look at these and noticed a few things.
The SM1 (Summon Monster 1) is on par with other summons, but just for fun I gave it a single use of a bolt web attack.
The SM2 is also on par with other summons, but had a skin that gave it Freedom of Movement; which was likely an effort to make immune to its own web attack. I replaced that with a spider skin that makes it immune to webs only. Gave it additional AC so its more in line with other summons.
The SM3 is where things got odd - it had 20 poison bolt attacks, so it was just going to stand there and shoot a DC 14 minor venom at things. I reduced its bolt attacks to 1; gave it a bite attack with small spider venom and 1d6 damage - it didn't even have a bite attack before at all. Gave it weapon finesse so its attacks hit more often.
The SM4 had 1d8 STR draining poison - meaning one hit could do 2d8 STR damage; that is just too good (better than higher level summons). So this was reduced to a 1d6 STR drain poison; twice as good as the SM3, but not better than SM5.
The SM5 had higher damage output than most elementals + poison. So shifted its STR down, gave it more DEX and Weapon Finesse.
This should improve the 1-3 summons but also probably brings the rest of the spider summons down a little in terms of damage at 4-5.
Open to feedback on these moving forward - but this should be a decent boost to the 1-3; probably not very noticeable on the 4-5 I hope. That said, this theme will soon be open as a sorcerer bloodline theme.
