Should we castrate DDog2?

[FaintlyBaffled]

We have 3 dogs. DDogs 1&2 are both entire working cocker dogs, DDog3 is a spayed staffieXwhippet bitch.
With DDog1 we were advised to leave him entire as he is an anxious soul and the vets felt that the extra bit of manliness would make him more confident. Given that he's never been a ladies man and has shown no unpleasant tendencies as a result, we have left him be, and indeed would continue to do so if possible.
DDog2 remains entire as he works during the season and this is generally believed to improve drive. He's also no problem WRT the ladies but has been noticeably more dominant around DDog1, so we had decided to have him done in the autumn.
At their annual check up it's been discovered that DDog1 has an enlarged prostate (he is 9 1/2) and castration has been recommended to stop any future nastiness. In discussions with the vet we feel happy that this will be the best course of action as DDog1 is older and less anxious than when he was younger.
The question the vet was reluctant to answer was whether we would be opening up a big can of worms if we had DDog2 done at the same time. In my mind I would prefer to go through the hassle only once as I feel it will be easier to restrict their exercise together and the hormone changes will occur at the same time.
Does anyone have any experience of this and would be happy to advise? The vets cagey response has left me wondering whether we may kick of WW3 rather than it being the easy fix I envisage

What was the question you asked that the vet appeared cagey about?

I mean I am confused about 'opening up a can of worms'. Do you mean their behaviour towards each other?

More dominant?
Are you talking about pack theory? That's been disproven.

No, sorry that wasn't very clear
The vet was cagey about whether we should castrate both at once or wait and do them separately.
As far as dominance goes, I don't mean in the traditional "pack theory" way. He will push to be in front, mark constantly over DDog1, will display an aggressive stance around him, growl at him when he gets in the car/ through the door etc. Don't get me wrong, there's never been any physical aggression between them (DDog3 won't put up with any such nonsense ) its more a sense of constantly having to be one up IYSWIM?

I think I would want to know what the 'worst' outcome might be if you neutered them at the same time to make my mind up. I presume there might be some cons if your vet didn't give you a definite answer.

Does your practice have more than one vet? Could you arrange another consultation with a different one and just say you wanted to discuss castration of both in more detail to effectively get a second opinion?

You can get an injected chemical castration that lasts a month and enables you to see how they will react if they were properly castrated.

The vet mentioned that peach but its shockingly expensive
The initial idea was to give it to DDog1 to see how his anxiety would be affected by castration, but on balance we've decided that however it pans out that he will have to be done.
I suppose we could have DDog2 jabbed at the same time as DDog1 is done and make our choice based on the outcome. DDog3 was, due to a long string of unfortunate events, spayed at completely the wrong time and it's affected her quite badly so I'm keen we don't have a repeat situation (particularly as it would be totally avoidable in this case)