= Solution
Comparable hydrostatic thermal escape requires comparable <Jeans escape parameter> $\lambda=GM_pm/(k_BTR_{\rm exo})$. For the same escaping species and $R_{\rm exo}\simeq R_p$,
$$
\frac{T_{\rm J}}{T_\oplus}
\gtrsim\frac{M_{\rm J}/R_{\rm J}}{M_\oplus/R_\oplus}
\simeq\frac{318}{11.2}\simeq28.
$$
Thus Jupiter at 5 au needs an exobase temperature at least about thirty times Earth's at the same irradiation to have comparable <Jeans escape flux>.
For the inner planet, the usable EUV power is $\eta\pi R_{\rm exo}^2F_{\rm EUV}$. If the binding energy per unit escaping mass is $GM_p/R_p$, <energy-limited atmospheric escape> gives
$$
\dot M=\frac{\eta\pi R_{\rm exo}^2F_{\rm EUV}R_p}{GM_p}.
$$
The time to lose a fraction $x$ of the planetary mass is therefore
$$
\boxed{t_x=\frac{xGM_p^2}
{\eta\pi R_{\rm exo}^2R_pF_{\rm EUV}}}.
$$
This neglects Roche-lobe reduction, radiative cooling, changes in radius and flux, and the planet's orbital evolution. If the gas is lifted only from $R_{\rm exo}$, replace $R_p$ in the denominator by $R_{\rm exo}$.
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