The objective of this work is to design a controller for a team of agents to accomplish cohesive motion with consensus on an agreed upon trajectory in both leaderless and modified leader-follower structures. The agent's dynamical model is considered to be governed by a general linear representation instead of a point-mass model which is commonly used in the literature. A semi-decentralised optimal control strategy is designed based on minimisation of individual cost functions over a finite horizon using local information. Decentralisation is achieved through incorporating interaction terms in the team members model. Minimisation of our proposed cost function results in a modified version of the consensus algorithm. Corresponding to the leader-follower structure, the utilisation of a corrective feedback from followers to the leader provides potential advantages in terms of improving robustness of the team to faults in individual agents. Simulation results are presented to demonstrate the effectiveness and capabilities of our proposed method in achieving user predefined requirements and specifications.