In this paper, the usual momentum- and coordinate-space distance criteria for creating nuclear clusters in transport simulations are readdressed by using a dynamical, covariant description in an off-shell Boltzmann-Uehling-Uhlenbeck transport approach. The free parameter of this clustering scheme is the cluster formation time, which is fitted through the FOPI data of low energy charged cluster multiplicities in Au+Au collisions at 150 A MeV, and 400 A MeV incident energies. The coalescence model is used to estimate the yields of the $$^3$$
3
H$$_\Lambda $$
Λ
, $$^5$$
5
H$$_{\Lambda \Lambda }$$
Λ
Λ
, $$^6$$
6
He$$_{\Lambda \Lambda }$$
Λ
Λ
single and double strange hypernuclei in central Au+Au collisions between 2, and 20 A GeV incident energies, giving comparable results to estimations from other methods.