A. Utilize separate credentials and profiles for each integration, one having "view All" to ties and the other having "Modify All" to Accounts.

B. Utilize separate credentials for each system with both credentials having the "modify all data" permission on the profile.

C. Use a single "Integration User" with profile settings restricted to "view All" for opportunity and "Modify All" for Accounts.

D. Utilize a single "Integration User" with the "Modify All data" profile setting enabled so that all integrations always have access to all data.