Does broader peak mean stronger absorber in UV/VIS?
The classical concept of  oscillator strength $f$ is useful here, but it should be used only in a qualitative way. This is defined as $f=a\int\epsilon_\nu d\nu$ where $a$ is set of units with value $4.3 10^{-9}$ if the extinction coefficient is in units  dm$^3$/mol/cm and $\nu$ is in wavenumbers. The maximum value of $f$ is unity and is close to this for an allowed transition in a dye molecule, such as rhodamine, but can be as small as $10^{-9}$ for a forbidden transition.  

In your case if two molecules have similar $\epsilon$ at some wavelength (or frequency) but one has a narrow transition compared to the other, then the one with the narrow transition will have a smaller integral and hence the smaller oscillator strength. In this sense only is the transition 'weaker', i.e. it is not the probability of  absorbing at a given wavelength that is being considered but that over all wavelengths, so it really depends on how you want to define a 'strong' vs a 'weak' transition.  In QM the transition moment integral is used instead of oscillator strength and gives a proper description of absorption.