I've included the link above to our IP warm up guidance document that should help with this questions. If sending only 10K on a dedicated IP, the need for warming is really minimal since the per-ISP traffic at the majors (Gmail, Yahoo, etc.) that would need warmed is going to be even less than 10K.
As far as sending from two platforms, as long as the campaigns are planned accordingly and following normal best practices there is no real concern. They should be using unique domains so as not to cause authentication or reputation issues with ISPs. There are many large volume senders who use multiple email platforms on a regular basis.
Hi and much thank you Pradeep!
I was out the office lastly but your message helped.
I also had thie document just wasn't sure how to understand it.
Have a nice week.