Selection pack of dry food?

[drspouse]

Our lovely 12 year old is off his dry food and has lost weight. He's happy to eat two pouches a day of Felix ('as good as it looks' not very good IMHO) but only the fish and he's doing a bit of moping and hiding which we suspect means he's not happy.
Can you get dry food selection or trial packs?
He still has all his teeth at least!
Cat tax - he decided the new bathroom fittings were his now!

I’ve not seen dry food selection packs but they would be a great idea. Our 4yr old cat has decided she can no longer face Iams dry food (chicken flavour) so I’ve been trying small packs of alternative brands. She loves Royal Canin Fussy Exigent (I bought a 400g pack) - the smell had her clamouring for it. But she isn’t so keen on Scrumbles chicken & salmon (though she is now working her way through the 750g bag, seeing as she’s eaten all the Fussy food ).

You can get small packs on zooplus. You could buy a couple and mix and match

Am I right that grains are best avoided or is that a myth?
I can see a few suitable on Zooplus - we already get his food from there so DH collects points.