It's like garbageout 3 all over again :/

I can't even hit an enemy before Boone kills everything in his path.

This is on very hard hardcoe (not that it matters in this game)

Please someone make a mod so the companions doesn't dominate the game thanks

+1000

Can only agree. I can't use any companions, because the game becomes WAY too easy. Enemies I wouldn't even be able to scratch, Veronica can easily kill barehanded without needing any help.

So I have just stopped using companions altogether, which is rather sad.

Verily.
When I saw our first battle with Veronica in tow I thought to myself 'OMFG'. She was one shot killing with her fist weapon like
some sort of super mutant on steroids and angel dust rage.

Some ways around it would be to remove weapons they do so much damage with. Easy way is to open the console (to see the items the companion has in the following
be sure you remove most if not all items you may have traded to the companion using normal trade means).

once console mode is activated select the npc (companion)
type:
showinventory
hit return/enter
you will now see a list of items the npc is lugging around, like the clothing, weapons and other special gear that normally would not show up in the trade menu.
write down the item codes you see for future reference in case you wish to reequip the npc with said item using additem (code) (amount).

to remove the items enter:
removeitem (code) (amount or number of items to remove)
example would be:
removeitem 0014823e 1 this would remove vernoica's armored robes .. the 1 is needed to indicate 1 item to be removed.

the item will be removed, zapped. gone.
Some items the companions are wearing/using the player char can not equip (must be hardcoded) so trying to 'borrow' some items by using
player.additem (code) (amount) won't work. I tried to borrow those ugly rags listed above to view the stats and they never showed up in my inventory.

You can do the same with the weapon so it is removed. Then equip the crazy over powered companion with some POS melee or ranged weapon.
THis you can do via the normal trade window now.

Until someone makes a mod to suit you this can work quite well. does for me plus now you can make sure the companion can only wear what YOU put in his/her
inventory box and not the default garb (which in Veronica's case I found extremely annoying and I could not bear having a companion running with me in rags).

Of course this only applies to PC users. Gameboy users can't use the console , I'm sorry.

In my experience you cannot remove those weapons from the NPC and have them stay gone because of the way they are defined in the follower's object definition.

Just open the geck and find the follower weapon definitions and decrease their damage.

A harder difficulty will make this problem worse. Since followers and other NPCs aren't affected, the player will do comparatively a lot less damage.