The complexity of a merger resides in striking a balance that satisfies the interests of the various parties involved. Thus, in these cases it is essential for independent experts to be involved so that they can mediate between the parties and set logical criteria to enable them to reach fair agreements. These are long processes and require a great deal of experience in these kinds of transactions as well as great leadership ability from the advisory team. It is also important for the shareholders and/or managers of merged companies to maintain cordial relations with little or no confrontation during the process as their relationship with the company in a professional capacity and/or as shareholders will continue after the merger.

In family owned companies , mergers must be carried out with conviction. These transactions do not result in ideal situations and require sacrifices from both companies, which are difficult to accept unless there is widespread awareness of the need for the transaction. If the parties are convinced that the merger is good for them, they will act reasonably in negotiations, making it easier to reach fair agreements. By their very nature, these transactions require a negotiating strategy based on establishing an ultimate aim, the merger, and achieving small undertakings along the way until a point of no return is reached that leads to the transaction being completed. In mergers that involve three or more companies, the complexities are still greater and one of the parties needs to co-lead the process together with the advisor of all the parties. Occasionally, when there is no party that should clearly play this leadership role or in cases in which there would be too many disputes if one of the parties involved took on this role, it may be worth considering bringing a new financial partner capable of playing this role into the new company.

The first obstacle is to reach an agreement on the swap ratio that will determine the share of ownership of the resulting company. The criteria that tend to be used are sales, EBITDA, EBIT, net profit or capital and reserves. However, none of these make it possible to arrive at fair swap ratios in themselves. In each case, it is necessary to take into account very different operational and non-operational criteria in order to establish a mechanism that includes different parameters from the profit and loss account and balance sheet.

One worthwhile way of reducing the likelihood of arguments is to separate out the non-operational assets from each of the companies to be merged beforehand. The same recommendation could be made for operational fixed assets, although in this case one needs to set the rent that the merged company will have to pay the respective owners for each of these assets. In the same way, in the uncommon cases in which the companies to be merged have very similar sales and productivity levels but different levels of capital and reserves due to different dividend policies, it is easy to find solutions for fair swap ratios. However, these apparently simple aspects of the negotiations make it possible to avoid any arguments only for extremely uncommon transactions in which the merged companies are practically twins. In all other situations, reaching fair agreements on the swap ratio requires a detailed analysis of the past financial statements of each company, as well as other aspects of the business.

Another complex aspect of these processes is power-sharing and combining both companies' workforces. After two companies merge, the new company obviously does not need two managing directors or two financial directors, etc. A merger thus often requires the dismissal of a significant number of managers. The fact that managers who are involved in the merger to a greater or lesser extent will be dismissed does not make it any easier to take decisions of this kind. In family owned companies in which family members hold some of the management positions, many mergers do not succeed due to failure to agree on these aspects. When the merger finally goes ahead, the swap ratio often indirectly determines which company's management team will take charge of the new company.

Synergies from cost reductions through economies of scale often lead to jobs being lost in other parts of the company (labor, sales network, administration department, etc.). These organizational adjustments and all the post-merger management aspects are another important challenge in these kinds of transactions.