What is the toghest fight V ever takes on?

I've been wondering this for a while now. What is the toughest encounter V faces / we face, or perhaps rather the strongest group V fights?

Important note beforehand is that I'm excluding Smasher, since I doubt anything beats him. Even with him as an obvious answer, I nonetheless found it intriguing to compare a handfull of groups.

The ones I came up with were the following:

1. MaxTac, the ambush on the convoy that is, not you getting a 5-star wanted level in open world, though they might not differ much.

Apex Predators, as the accompanying OST nicely reminds you. Made to take down some of the potentially strongest, if not at least most dangerous individuals, that have lost control over themselves.

Plenty of implants, not rarely as lethal as who they're send after

2. FIA Spec Ops at Orbital Air Lunar Spaceport. Goverment's Elite (presumably). Dunno too much about them to be honest, but I imagine they're likely no pushovers

3. Arasaka Elite in (Don't) Fear the Reaper. (Gotta confess, haven't actually played it myself yet. My one playthrough where I did play through most the endings I have ample relations with Johny, but picked different options during Chippin In, in an effort not to be mean, though I've certainly heard the ending ain't a walk in the park on higher difficulties.)

Just wondering how a private defense Corporation measures up to a governental military branch measures up to a cyberpsycho hit squad.

Btw, if I missed any obvious encounter's, which I have little doubt I may have, feel free to remind me