Constants? Yes, no problem (switch load order if it doesnt work). Arics? A big fat noooooooope. Im no expert but based on the files both modify Id say Arics and Leos are mutualy exclusive unless someone does a fair bit of work to include one mods functionality in the other, but even then their going to have to resolve some contradictions.
And I agree with RustyRoost, Romi should really come out with Grateful, considering how much effort can potentialy go into making a character match the description. The quest step to find the toymaker could use a hint on where to go as well. As I recall I despite "a fair number of attempts" I was unable to figure out what 2nd potion was needed, and where to go. Luckily the walkthrogh in the mod files had the anwsers so I wasnt stuck.
Also, if at all possible, a description on what the new abilities do in the items (or somewhere else) would be a good addition. Spear adds first strike, but what does first strike do? The bows ability needs to add more than 2x damage or armor piercing for it to be usefull due to action economy. You dont want to use an ability that spends a turn if you end up doing less damage than if you just attacked twice.
Overall though, its a nice mod that spices things up a bit and makes exploration feel more like what it used to be in Strive before you figure out you can just spam invigorate and then camp+sedation everyone back to normal when your done.