Different capacity lipoly in parallel - charging and discharging

I have a closet type light that has a long thin ‘gum stick’ lipoly battery in it. Opened it up. Supposedly was 1500mAh by the printing on the jacket. Did a capacity test and it came out at 650mAh after a year+ of regular use. It barely lasts a week anymore. Light pulls 0.4A

I have another larger lipoly of ~3000mAh. Can I parallel wire both of them into the same tabs on the electronics board and not end up with problem?
I know they should ‘balance’ to the same voltage right away. Initially I’d wire them at similar voltage state.
Would they discharge evenly, or would the small battery get over discharged?
I’d use the stock USB charge port as designed. Would they charge evenly?

I’d think so, but I haven’t done something like that. I generally try to keep cells matched.
Thanks.