I recently did some childcare testing, and I know you all use birds, but if you are in the right biome, and don't mind catching wild animals for testing, there are some wild animals that are under the size of dogs, but over the size of cats etc. And they train offensive combat skills at a pretty rapid rate.
I found pitting single wild mandrills, coatis, koalas works. I even took some riskier animals and pitted them into the test chambers, like dingos, coyotes, lynx, and bobcats.
Just throw in some wild turkeys every now and then for the safer training kills.
I'm using a 2x2 chamber designated as a meeting zone, and an adjacent bedroom. Although this was only a working design, i'm testing various other designs now.
Out of 4 test subjects, 1 died fighting a mandrill. The other 3 survived and are at skilled/talented in wrestler, and around adept in fighter, with perhaps 7-8 kills each so far.
I'm doing more science on it now, but it seems that the tame animal plan people are using works well, but very slowly, while being relatively low maintenance. My method seems riskier, takes comparatively more effort, but not lots, but seems to be producing much faster results, just not much in terms of defensive skills, although it is training them too (possibly at a similar rate to the passive method).