Allies in Warhammer

Allies, a way to circumvent your army's weaknesses or a way to include something fun & characterful?
I saw a thread on the Facebook middlehammer group page that discussed allies, this got me thinking about how I feel about allies, how I used to feel about it back in the day & how our gaming group used allies.

The very first time I used allies was with my Chaos army back in 4th edition, this was in the very beginning of my warhammer experience.
I owned a few models such as a Chaos Knight champion (used as a lord), plenty of beastmen & warriors (monopose plastics), a sorcerer on disc & nothing else, I wanted to field some cavalry, but Chaos cavalry back then was only available as metal models & for a 12 year old it was a lot of money to get a full unit, but allies were there to save the day, I bought 2 boxes of skeleton cavalry, it cost the same as 2 Chaos Knights, but gave me 6 models instead, enough to field a unit. I made one a standard bearer, gave them the Doom Rider banner & then they were a mainstay unit in my army for many, many battles, even after I had bought a full unit of Chaos Knights these were part of my army until I had my harpies & daemons (all metal ofc) as well.
It was a good unit, able to run through terrain & it hit hard with autohits @ S5, yet I never felt like I was cheating when using this unit, not even when one of my characters started using Book of Ashur to get Necromancy magic to help them out, it felt like it was part of the army.
A friend of mine who played Bretonnia had some Lothern Sea Guard in his army, not because it was the obvious better choice when compared to his peasants, but becaue he wanted to use his neatly painted elves from the 4th edition starter, no one complained about allies!
But then I met a greenskin army, it was a new guy to play against, he knew one in our group & was welcomed to join in on the fun, he used some Hobgoblin allies in his army, this made him ignore greenskin animosity & it meant he basically had a bunch of undercosted units without their drawback & this time it felt like someone was cheating when using allies.
It didn't stop me from using allies, but I always used allies that felt like they fit in, as an example:
My Chaos warriors had both daemon & beastman allies, as well as Skaven (no war machines though), mostly it was due to the 4th edition book so I had the models, but it felt right to ally in these kind of units, heck I even tried a lone greater daemon once, but only for a special scenario.
My Empire had a unit of Wood Elf Archers led by a champion with Hail of Doom Arrow, sometimes they switched for a unit of dwarf slayers, both of these units added something I already had access to, but was both better at it & still felt like it fit thematically, Humans have allied with Dwarves & Elves on multiple occassions.

The Warhammer World is full of stories about desperate alliances, during the Great war against Chaos, humans allied with both Elves & Dwarves, however there are even stories of greenskins attacking the Chaos forces, knowing full well what  would happen if Chaos won.
In the siege of Quenelles Wood Elves allied with Bretonnia.
At la Maisontaal Abbey an Undead & Skaven Alliance was beaten back by Bretonnians.

Choosing allies in warhammer is very easy, you get to pick allies from certain books, 25% of your army may be anything you want from those books & well this has led to several misuses in the  World of Warhammer.
Over the years I´ve seen allied Greater daemons, Wood Elf armies with Dwarf Organ Guns & said Dwarf armies include high level spellcasters etc etc.
This have led to some groups banning allies altogether.

Imo allies are great, it's a way to add flavour to your army, to paint up a unit from another army just because you like it, or to just win at all costs...
If you use allies for certain scenarios, or have a great theme, then great, if you include them just to counter a weakness in your army or to get away with something your army aren't allowed to use normally, then maybe not so great.
If you've read my blog before you know what rules my gaming group used when it came to Warhammer 5:th edition, if not, then here´s a reference:

Minimum 33% RegimentsMax 33% Characters (Bretonnia may have 50% characters)

No unridden large monsters

No allied characters or warmachines except Dogs of War

No Power 3 spells
Magic Items with a points value of more than 50 cannot be included

Only one war machine, for each regiment in the army
No Fly High

We got around the biggest problem of allies by not allowing warmachines or characters (Dogs of War was the obvious exception).
Imo one of the things allies shouldn't be used for is to use extremely powerful characters/war machines to get around the normal restrictions or weaknesses of your army.
You want some shooting with chaos, fine, ally in some Dark Elves, but avoid the Bolt Throwers.
Want magic with Dwarves? Ally in a lowbie Empire wizard & his bodyguards (maybe some halberdiers?), make sure you add a backstory to it.
Mercenaries is another explanation, but do those mercenaries have to be led by Tyrion or Teclis?
My Point is that usually there is a good explanation for an alliance, it can be anything from a common enemy, or old kinship (Dwarves & Empire come to mind), but one should choose allies in the spirit of the game, warhammer is already an unbalanced game, you don't need allies to make it even more unbalanced.
Alliances between races that are not only believable, but probable, is the best kind of alliances.

Proper allies!

Some alliances I find probable:

Chaos: Allying between themselves is very probably, other probable allies include Dark Elves, greenskins & Skaven.

Empire: Dwarves of course, Dogs of war, Bretonnian Questing Knights would work well too.

Bretonnia: Empire & Wood Elves

Lizardmen: None

Greenskins: Skaven

High Elves: Empire or Wood Elves

Dark Elves: Slaaneshi Daemons

Dwarves: Empire

Wood Elves: Bretonnia

Undead: Chaos, have also been known to ally with Skaven

Chaos Dwarves: Chaos, but also greenskins

Skaven: Chaos, Undead

I would use either the rules we have for allies (no characters or war machines) or make the allies look like small contignents, so maybe a lowbie character to lead them, some of the more common troops & max 1 of something rare (Empire for example could be a unit of Halberdiers, a level 2 wizard & a single war machine). Using allies can be great fun, it allows you to be creative, to field something new, but always remember the first rule of warhammer, both players should have fun!