The policy on IPv4 address transfers due to mergers or acquisitions already existed when the policy on transfers for other reasons (2.3.2.18) was implemented. The latter incorporated some important observations that are not included in the former, even though some of them are present in documents other than policy documents. For example, the fact that transferred resources will no longer be considered as legacy resources., Twhisch is described in the LACNIC Bylaws.
For reasons of consistency, this should also be reflected in the policy document.
The same is true for the restriction of two consecutive IPv4 address transfers, awhich is already specified in policy 2.3.2.18.