Fortran and OpenMP thread groups for independent tasks - multithreading

Question

I need to run two independent tasks using OpenMP. One of them is way more involved than the other, so it would be ideal to split the available threads such that the more complicated task uses more of them. After these two tasks are finished, I need to use both of their outputs. I am not entirely sure if this can be done with OpenMP, so any suggestion would be very useful.
This is an attempt to illustrate what I need. There are two independent suboutines with separate inputs and outputs. Subroutine mysub2 is more complex than mysub1. It has multiple nested loops, so it would benefit more from having more threads running it. Out of 6 threads, I would like to assign 2 of them to execute mysub1, and 4 of them to mysub2, simultaneously. After getting each subroutine outputs, z1 and z2, both of them are used to compute z3.
In this attempt I was trying to assign threads 0 and 1 to task 1, and the other 4 to task 2. Obviously, this doesn't work as intended because it runs mysub1 twice and mysub2 four times, but I have no idea how to achieve what I need.
module mymod
implicit none
contains
subroutine mysub1(x1,y1,z1)
! Element-wise product of vectors
real,intent(in) :: x1(:),y1(:)
real,intent(out) :: z1(size(x1))
integer :: i
!$omp parallel do private(i)
do i = 1,size(x1)
z1(i) = x1(i) * y1(i)
end do
!$omp end parallel do
print *, 'Done with mysub1'
end subroutine mysub1
subroutine mysub2(x2,y2,z2)
! Matrix multiplication
real,intent(in) :: x2(:,:),y2(:,:)
real,intent(out) :: z2(size(x2,1),size(y2,2))
integer :: i,j
!$omp parallel do private(i,j)
do i = 1,size(x2,1)
do j = 1,size(y2,2)
z2(i,j) = dot_product(x2(i,:), y2(:,j))
end do
end do
!$omp end parallel do
print *, 'Done with mysub2'
end subroutine mysub2
end module mymod
program main
use omp_lib
use mymod
implicit none
integer :: tid
integer,parameter :: m = 2
integer,parameter :: n = 3
integer,parameter :: p = 4
real :: x1(m),y1(m),z1(m)
real :: x2(m,n),y2(n,p),z2(m,p),z3
! Setting total number of threads to 6
call omp_set_num_threads(6)
! Assigning arbitrary values for illustration purposes
x1 = 1.0
y1 = 2.0
x2 = 3.0
y2 = 4.0
!$omp parallel private(tid)
! Getting thread number
tid = omp_get_thread_num()
if ((tid == 0) .or. (tid == 1)) then
! Task 1 to be executed in two threads, tid = 0,1
call mysub1(x1,y1,z1)
else
! Task 2 to be executed in four threads, tid = 2,3,4,5
call mysub2(x2,y2,z2)
end if
!$omp end parallel
! Using z1 and z2 (serially, no need to parallelize)
z3 = sum(z1) + sum(z2)
print *, 'Final output', z3
end program main
Of course, this is just an example. I know I don't need to use mysub2 to do matrix multiplication. I'm just trying to illustrate that mysub2 is more complex and hence, it would be ideal to use more threads for it, without having to paste several hundred lines of the actual code I have.