Many intergovernmental organizations have a similar recruitment model with limited term contracts for most staff members. (My experience is with EMBL but I don’t think the practice is limited to research-focused organizations.) The explicit aim is that staff members will join (possibly on secondment from national governments), bring their existing knowledge and share it with other staff from other countries, and then return to their home country bringing new experience to improve things there too.
The packages of benefits and perquisites offered by these organizations include some that EA organizations should consider duplicating if they want to encourage “tour of service” style employment.
Relocation assistance not only before starting the job but also after the end of the contract period.
Travel subsidies to encourage continuing links with the home country (and with the seconding organization, if applicable).
Dependents allowance, to compensate for the fact that e.g. if one spouse relocates to a foreign country for work then this lowers the earning potential of the other spouse.