I just did some calculations for the demoman. I left out the shields, because their hit damage is really low compared to other weapons and takes a long time to recharge. The guaranteed critical hits also don't help, because of the reachrge time. I did not consider the Ullapool Caber, because it is such low base damage that even the explosion hit will not help it to be better than other melee weapons of the demoman. If I talk about fully upgraded melee weapons, you have to remember, that a shield needs to be equipped in order to be able to upgrade damage. And finally, if you use the sticky-bomb launchers (either one) you should ALWAYS only lay out 8 bombs, detonate them UNDER the tank and then shoot another 8, regardless of how big your clip is. This is because the bombs do more damage if detonated within 5 seconds. These 5 seconds usually suffice to lay out 8 bombs, with the only exception being the standard sticky bomb launcher, where you only manage to get out 7 within 5 seconds. As soon as you upgrade it, that doesn't matter anymore.
This time (compared to the sniper calculations above) I factored in critical hits with their base probability. This probability actually goes up depending on the damage done within the last 20s. If you are striking at the tank, you do substantial damage, so all damage per second values except for the Eyelander, the Claidheamh Mòr and the Persian Persuader are actually higher than the provided values, though I suspect not by much.
In general can be said, that the gap between these values is even wider when comparing melee with primary/secondary weapons, because melee weapons get up to 50% higher critical chance with caused damage, compared to only 10% for non-melee weapons.
For the grande launchers I assumed that you would restock your ammo, when your carried ammo is empty, but your clip is still full. I also assumed (for all calculations) that it takes 15s to get new ammo. I used average values for the damage, but you have to keep in mind, that the damage done depends on how you hit the target.
The Grenade Launcher:
- Stock: 90 dps (down to 55 with restocking time)
- Fully upgraded: 291 dps (down to 203)
The Loch-n-Load:
- Stock: 82 dps (down to 54)
- Fully upgraded: 333 (down to 233)
The Stickybomb Launcher:
- Stock: 139 dps (down to 94)
- Fully upgraded: 203 dps
- I did not provide a dps value for fetching new ammo, because by the time you emptied your ammo, you have done about 11250 of damage. This also took you 55s to do. With the help of your team, the tank should be destroyed by now.
The Scottish Resistance:
- Stock: 146 (down to 108)
- Fully upgraded: 202 dps
- Again: One load of ammo causes 15700 damage. (Though I doubt that you will get there, because that takes 78s to do)
The Bottle: (or any other standard melee weapon)
- Stock: 106 dps
- Fully upgraded: 296 dps
The Eyelander: (or any other weapon that behaves like it) Also, the Claidheamh Mòr, the Half-Zatoichi and the Persian Persuader:
- Stock: 81 dps
- Fully upgraded: 228 dps
The Scotman's Skullcutter:
- Stock: 127 dps
- Fully upgraded: 355 dps
The conclusions you draw from this should be your own, because there are many combinations possible here. Also, you can cause an inital critical hit with the help of a shield, as well as launching grenades when you are further away from the tank. A good combination I see in here is to use the Loch-n-Load until you are close, or whenever you are separated from the tank and then switch to the Scotman's Skullcutter when up close.