Link Chain - Budget link building.

Suppose you have 3 sites (2 of the sites link to 3rd sites from homepage and siteweide) , all sites are hosted on different IP's. I then buy a guest post and put 3 acnhors to each of these websites. One guest post will give power to 3 sites as 3 links are allowed in guest post. IS this strategy smart or dangerous?

shared link profile is surely a footptint, at surely least theorically,
even if it's not used/detected now it could be anywhere in the near future,

try to diverse the source of links for each of the domains along the way at least,
keep a ratio of 20-50% of the same linking websites for each of these websites and you're good to go

3 sites is no big deal, I think you'll be safe (especially if google can't link all sites to you)