KID wasnt ranked high at all, when the UFC signed him in 2010, KID's last relevant win was against yahya, almost 3 years prior.
you realise melendez and alvarez both garnered their rankings by fights in japanese promotions, right? melendez was the #2 guy at LW before ishida and thomson beat him. alvarez was the #2 guy before aoki beat him the first time. it has nothing to do with bias, just common sense. the kawajiri/melendez rematch was signed before zuffa purchased SF.
gomi had 20 more pro fights than florian when they fought, age =/= fight age. i don't know if florian was at his absolute peak, but he sure was looking a lot better than gomi. gomi was coming off of a close fight with tony hervey, florian was coming off of one of the best performances of his career against guida.
florian reached the #3-4 spot at one point in most rankings, he was never underrated in terms of rankings.
Yamamoto was still ranked high when ufc signed him, many on this forum were excited about his ufc debut. He was like randy couture when he came to fight sylvia for the hw belt, couture was unranked in hw and his last good win was 3 years prior, when thiago silva comes back next year his last win would been in 2009, he might not be ranked but we all know he is animal at 205 and is up there in top10, mark hunt didnt have any significant win until a year ago since 2006, long layoffs or not winning a while means you suddenly just lose all your skills, plus that warren loss and golaev losses were controversial, not like they got cained for 5 rounds. Kid and gomi were still young not like there were in late 30s when ufc signed them, travis fulton has over 300mma fights still going strong, as long as there are no major injuries and you dont win or lose fights by absorbing punishment, number of fights is just a number and neither gomi or kid were known to cabbage their wins.
Kawajiri vs melendez happened under zuffa, ultimately zuffa had right to cancel not only that fight but whole show if they wanted, i mean they released their hw champ without blinking an eye.
Sure Alvarez got his ranking over in japan, but since then for years him and other fighters fighting in usa, were still ranked lower than fighters fighting in japan, we had talk here how aoki will beat ufc champion just few years ago, then he fought melendez and alvarez 2. And apart from melendez and alvarez there were bendo, maynard, pettis, guida, miller, diaz, cerrone, varner, lauzon, tons of other fighters ranked lower than aokis, ishidas and kawajiris fighting stateside. Gezias and ribeiro were perennial top10 until they came to fight in usa and lost to no name fighters, gomi was ranked #1 before and after he lost to not top10 in diaz in usa. Most of 145-135 top10 fighters until recently were for most part from japan, small guys from wec didnt get the same recognition, but now we know those guys were animals, benavidez, jorgensons, aldos, winelands, tons of others. Now they rightfully so ranked in top10, in last few years it went from fighters fighting in japan having monopoly on top10 ranking in lower weights to now fighters fighting stateside dominating the top10.