Cos you're not going to be getting anywhere near the correct amount of vitamins and minerals for a racing dog from some boiled vegies and kibble (there is no such thing as a "complete" food......no matter what the packaging might try to tell you).
Vegies are a waste of time and effort IMO. Even boiled they will go largely through the dog undigested. Plenty of trainers will disagree with me though.

Try adding Black Tar or Stockgain on alternate days and Kohnkes Gold every other day.
Don't add the same thing every day as you risk overdosing and/or getting an accumulation of certain minerals/vitamins......and certain vitamins/minerals "clash" and will cancel each other out to some degree.

Greyhounds get energy from fat (primarily)....so eggs and pasta on their own aren't much good for a race day snack. Again, just my opinion.

They should be fed minimum 6 hours before they race and I would give a small amount of red meat with the eggs and pasta.
It should be a small meal. A handful in total.

As Carole mentioned, diuretics are a BAD idea! Give them good old milk and water after a run. They will pull up a lot better.

They aren't. GRV released a statement recently that suggested they could cause a rise in arsenic levels in a greyhound, not cobalt levels.

Hi Simon
Firstly good luck for future and well done for being honest and asking !
It's the only way of learning (possibly? , you decide what you keep and throw away )
First thing I'm only new myself with a couple of race starts and no wins yet either
So I shouldn't really comment as experience is what I lack greatly , but everyone has an opinion and who knows what could help you .
I've used Advance and no longer rate it , it's ok but it's a middle of the road kibble
Even though it's priced higher end , it contains meats in it that actually aren't advertised on it ! E.g. It's says chicken bag , but actually on the back it has lamb beef and any other thing that might make its way into the bag , trust me look at ingredients on the back , all cheaper bags contain all the meats that are possible !
I like MFM (meals for muts) Duck and turkey it's their best bag (contains sweet potatoe,which is the highest energy vegetable you can get !) and I blend it with Canidae (salmon) both grain free , it assist with inflamed muscles !
And both only contain what meats are advertised on the front of the bag !
A lot of Poeple will say it's only filler who cares or top trainers use bread only
I believe those same dogs would run on meat pies , me or you do not have grp or city performing greyhounds
Again up too you and everyone's own preference
Just passing on what I've noticed in the difference of my greyhounds looks and behavior from changing kibbles
Your milk skim and meat kanga is obviously very lean on fat content
Fat is energy
Full fat or normal powdered milk e.g. io milktech lamb milk replacer and chicken mince added to meat content could be a different option also for morning meal and main meal meat content.
I used to try all the energy or chemical replacements and vegetables
Now I just use black tar and calci + by jack with cod liver oil and an egg every 2nd night
And coconut water for rehydration after runs or over their meals
These are natural options and fast or quick to prepare
I know trainers who don't run their race dogs all week , just lead walk in between races
I know some who say run every day
There is no right or wrong , up to how the dog responds
At present you do 18 km walking
3 hours running a week on top of the race
All up in looking and just having a guess , you might have a diet low on energy and a pretty good work load to say the least !
I might be wrong but consistency is def not happening for a reason ......
I'd up the energy intake and minimize the work load so it becomes quality work not volume work !
E.g. Walk 10-15 min daily ,(the first 2 days after race being most important)then 3 days after or mid week to your next race , you could do a 300mtr straight drag lure run or a hard free gallop .
They will rip in more then doing it daily and be more on their toes and ready to go,thus (fingers crossed) could give you and them a better chance at performing better or more consistently!
Remember , they are racing , not pretraining , they are fit already

Lastly you need to know your greyhound inside and out
Starts with bloods and finishes with blood !
You should also have a greyhound vet check them every week !
Every week !
If you would like me to set you up with a greyhound vet let me know and I will do it
They are both based at Richmond area
Garry carter and Matt kwong are the only guys you need to have checking or operating on your dogs !
And you'll need a laser also of some kind or someone who can help you in this area
But loading your dogs and driving to receive this type of treatment will become a tedious exercise and you are better off getting one yourself !
Hope some of this helps
Again I'm new myself , throw away what you don't like
Good luck mate in future , great sport !