I'm confused as to why someone would vote for Viking Berserkir, Samurai, and Panzer as the game's single most underpowered unit.
At the time the Berserkir appear, they're the strongest unit in Europe and suffer no naval attack or river crossing penalties and can wreak the same havok they did in real life. I suppose they go obsolete quickly, or are useless on Emperor when rivals learn to build heavy pike garrisons? Maybe the vote is due to having to the time spent researching civil service before the next batch can be built?
The Samurai are awesome, especially
in the context of RFC, since they are powerful offensive units that are difficult to dislodge from cities thanks to their UP defensive bonuses.
Tanks all start with the Blitz promotion, making warfare instantly more deadly, but Panzers start with Commando and don't require oil. It also gives +25% against rifles and infantry, which makes it overpowered if anything. With rails built in Scandinavia, Germany can conquer the entire region from the Nordkapp to the Oresund in two turns with a large enough tank corps. The Commando promotion negates General Winter, and the presence of rails in Russia leads to their conquest all the quicker. Germany is the only country capable of invading Russia without massive casualties due to General Winter (except Mongolia, but Mongolia will suffer massive casualties due to suicide Keshiks being thrown at walls of pikes), and the Panzer makes it so. Panzers are probably the least weak UU in the game.
The "passive" UU (workers, passenger ships) are kind of unfair to compare to the offensive military units, since their civs aren't meant to be played as warmongers. I think the Carrack is an amazing unit since it can transport useful units long before your rivals can do so with galleons and astronomy, giving Potrugal a HUGE lead on the colonial resources game if planned well. I've never bothered with the East Indiamen much, mainly because my colonial empire has already taken form before I get them - my galleys reach South Africa and India/Australia well before Astronomy (cities from which I build more local settlers), and my caravels secure the Northern Mexico spice for me (after conquering it
), also giving me a New World city to build settlers from - Astronomy often doesn't factor into my colonial strategies until the rest of Europe is there - I often steal it from the French on the turn they discover it (over-ocean trade and extra buildings on settlement are admittedly very useful, though). However, the East Indiamen can ferry two weak cities either vulnerable to natives or slow to grow (2 settlers and either 2 defenders or workers) or one powerful city capable of defeating natives (1 settler, 2 defenders, 1 worker) at a time, giving them a solid advantage over rival civs. Plus, they can hold their own against privateers, making them a stong assett, even if not a powerful military unit.
My vote would be on one of the New World civs units - probably the Holkan. All of them are weak, but the Aztek & Inca at least have extra city attack, giving their warriors a slight chance at recovering a city if it has been captured. When I first saw the Persian Immortal was a mounted unit rather than as a spearman/swordsman, I think I found myself saying "What? That's weak!," so I think I can make a case for them as well.