Channel Alternator

I am trying to use an interlace controller inside another controller (ForEach OR Loop OR any other), so that each of the samplers (which is an HTTP request) in the Interleave controller runs once, and the test exits the "external" controller once the last sampler is executed.

My test plan looks somewhat like below

test plan
--Loop controller ( with loop count = num of requests in Interleave Controller)
----Some test elements
----Interleave Controller
--------HTTP requests (count = n, with some differences)
----Some More test elements

The test plan is to test several test scripts of many REST services (with some changes to the request data, etc.), so some services can have 2 scripts, which can have 10.

So is there a way to get the number of samplers under the interlace controller? OR the best design for my test plan.

thank