well sense you are listing six tubes in your either talking about a 150watt amp or preamp tubes. if it is the pre amp tubes it doesn't make any difference what brand they are
It can be ok if they aren't to far off in bias. the tubes won't heat up too much probable since the stock bias on recto is fairly low, if the amp isn't modded with a bias pot already.
I had 3 sovtek and one mesa tube in my amp, and never got an issue, but at the time i put that mesa i didn´t knew shit about tubes, and the amp sounded great still. but if a tech tell you don´t do it, you wanna listen to him.