The LCLS-II is a future upgrade of the Linac Coherent Light Source (LCLS) at SLAC. It will include two new Free Electron Lasers (FEL) to generate soft and hard X-ray radiation. The 2.9 km LCLS-II lattice will include 1/3 of the SLAC linac located just upstream of the LCLS-I, a dogleg and bypass line around the LCLS-I, a 2.4 degree bend section, beam separation and diagnostic regions, and the FEL undulators and dump. The LCLS-I operation shows that occasionally the beam phase space may be significantly mismatched due to focusing errors in the beamline. This requires correction to ensure good beam quality in the undulators. Similarly, the LCLS-II must have lattice correction system with a large tuning range to cancel such errors. Since the different LCLS-II regions are connected using matching sections, the latter can be used for correction of the mismatched lattice functions. In addition, a large tuning capability is required to provide a wide range of focusing conditions at the FEL undulators. The capability of the LCLS-II lattice to compensating focusing errors equivalent to up to 160% of mismatched beta function and to providing matched optics for a large range of undulator quadrupole strengths is evaluated resulting in specifications for the required range of magnet strengths. Show Partial Abstract