It sounds like the necro summon is scaling with your summon points which I think is quite cool.

Summoner:

>200 armor, 1300 hp, 130 damage

Non-summoner:

>120 shields, 680 HP, ??? damage (65 damage estimate)

A little more than double, seems right. Should be affecting damage as well in that case. I think you're doing a poor job of trying to argue that summoner is underpowered if doubling this spider's health & damage is a result of those 10 summoner points.

I also feel like you're selling the incarnate a bit short. You get the four infusions

- Power (SKILLS: whirlwind, bullrush, DAMAGE:+25%, ARMOR BOOST)
- Farsight (SKILLS: ranged attack, DAMAGE:+25%, MAGICAL ARMOR BOOST)
- Shadow (SKILLS: chameleon skin, corrupted blade, BONUS MOVEMENT SPEED)
- Warp (SKILLS: tactical retreat, DODGE:+15%)

Plus all the elements!

- Fire (SKILLS: fireball, fire immunity)
- Electric( SKILLS: eletric discharge, electric immunity)
- Water (SKILLS: restoration, water immunity)
- Poison (SKILLS: poison bolt, poison immunity)
- Oil (SKILLS: fossil strike, earth immunity)
- Blood (SKILLS: mosquito swarm, ARMORs:+15%, +1 warfare)

I believe there are source infusion possibilities as well

- Necrofire (SKILLS: fireball, epidemic of fire, 20% fire healing)
- Cursed electric (SKILLS: electric discharge, closed circuit, 20% electric healing)
- Ice (SKILLS: restoration, steam lance, 20% water healing)
- Acid (SKILLS: poison bolt, acid spores, 20% poison healing)

Being able to cast top tier elementalist skills seems pretty badass to me, but I haven't gotten there myself yet so I can't speak to its effectiveness.