Tiffins use the common 21 types of questions. As Tiffins only use one VR test your child will only see 12/13 types from the 21.
Walsh are known to be quite hard, so scoring 90% is very good. They do use brackets in 2 types of maths, which the real test will not. [types G and I as identified by IPS]
Other relevant pulishers include
IPS [short 30 minute tests.]
The Tutors, [ a good middle range of full tests]
Susan Daughtrey [ the ones with 4 tests in each pack, formerly known as Bright Sparks] , closer to the difficulty standard of the the real tests.
Take a look at my sticky in the Bucks section.