What is the minimum it takes to do Ubers as a summon necromancer? I'd like to make a character where I do basically everything with it, chaos, baal, MF, key runs, torch runs etc. This would be a ladder starting character so gear would not be top tier during the torch run, like 5 plain summon skillers, shako, enigma, hoto, homunculus, trangs gloves, whatever I can get for boots and belt. Probably wouldn't even have CTA. Merc would probably have obedience, duress, tal helm or something similar.

For this example I'm saying that the most expensive runeword you could have is Enigma (would not consider it without reliable tele, revives would never make it) and maybe like +15 to summons. No Beast, no Infinity, preferably no situational revives like Urdars but they're probably necessary.

Is it even possible? I've played several summon necros in the past but never did run ubers successfully.

In my opinion (only did end endgame gear summoner)
No.

Merc will die
You need Urdara for crushing blow since merc dies

Will be very hard in my opinion

you need a lot of Urdara for their crushing blow I have seen it done might take a lot of trial and error before you are able to do it well.

Google that exact sentence and do a little research.. It's been done before with a summoner