The Kitsune use alternate paths for other schools. Secrets of the Empire tells on page 249, in the Mantis section, and on page 250, in the Minor Clan section, a comprehensive list of 4th edition versions of schools and paths that are (always) available to the Kitsune:
School
Kitsune Shugenja (Shugenja)
L5R 4th Edition Core Rulebook. . . . . . . .219
Alternate paths
Children of Chikushudo (Shugenja)
The Book of Earth . . . . . . . . . . . . . . . . . . .196
Kitsune Artisan (Shugenja)
Strongholds of the Empire. . . . . . . . . . . . .25
Kitsune Ranger (Bushi)
Great Clans. . . . . . . . . . . . . . . . . . . . . . . . .170
Kitsune Summoner (Shugenja)
The Second City. . . . . . . . . . . . . . . . . . . . .N/A [sic!]Correct pointer: The Second City - The People, p99
Minor Clan Alliance Diplomat (Courtier)
Strongholds of the Empire. . . . . . . . . . . .169 this doesn't demand you to be a courtier at all. Only pre-Mantis.
Looking at The Great Clans p.170, the Kitsune Ranger alters the Tsurushi school (or any other Mantis Bushi) by swapping the 2nd Rank school skill for an alternate one focussing on hunting and stealth as well as spotting people. This makes the Kitsune Ranger the mentioned excellent scout on the cost of potential damage dealt.
In its description, it also says that in the time before the Kitsune joined the Mantis, this path is/was open to Kitsune (and Kitsune-allied Ronin) of any bushi training, replacing the original school's 2nd school skill (or granting it for non-schooled Kitsune), thus allowing to use other schools.
Especially well it seems to pair (other than Tsurushi Archer) with the Hiruma Bushi, Moto Bushi, Bayushi Bushi, and Daidoji Bushi, who all get the chance to pick up stealth as a School Skill. In this the Hiruma take a lead on the statics as they get both Hunting (a requisite for the path) and Stealth as School Skills anyway, the Moto taking a close second because the Unicorn and Fox are somewhat close and the Moto Bushi get Hunting - through cavalry isn't something the Kitsune had since the departure of the Ki-Rin. Some other minor (or previously minor) clans also make good combinations but there would be too many to go through.