Datasheets rate NTC inrush capability as a max capacitance at a reference voltage. Reverse-calculate the implied one-shot energy and compare with the circuit's actual ½CV².
Peak current at switch-on is I_peak = V / R_total. With no external limiter, R_total is just ESR + source/wiring R — often tens of milliohms, giving hundreds or thousands of amps in the first microseconds.
Energy dissipated in the series resistance during charging is exactly ½CV², independent of R. Only the time over which it's dissipated changes. Your limiter must be able to absorb this entire pulse.
NTC inrush limiters (e.g., Ametherm SL-series) present a high cold resistance that drops sharply as they self-heat. Size the cold R from the target peak current; check the one-shot joule rating against the energy figure above.
Pre-charge resistor with bypass contactor/MOSFET is the cleanest approach for persistent loads — size R for acceptable peak current, verify the pulse power rating (typically 10× steady rating for <100 ms), then short it out once V_cap approaches V_dc.