The average agency uses 8 to 12 different SaaS tools. Project management, CRM, invoicing, time tracking, contracts, messaging, storage, accounting. Each costs between 10 and 80 euros per user per month. The total adds up fast, and the complexity even faster. Facing this fragmentation, two philosophies clash: best-of-breed (choosing the best tool in each category) and all-in-one (a single platform for everything). Let's break it down.
À retenir
- Best-of-breed multiplies tools but also the hidden costs of integration.
- An all-in-one tool offers data consistency no patchwork can match.
- The real selection criterion is the fluidity of the team's daily workflow.
The best-of-breed approach: the promise of functional excellence
The idea is appealing: for each need, pick the most powerful tool on the market. Asana or Monday for projects. Pipedrive or HubSpot for CRM. Toggl or Harvest for time tracking. Pennylane or QuickBooks for invoicing. DocuSign for contracts. Slack for communication.
The theoretical advantage is real. Each tool is optimized for its function. The interface is designed for specific use cases. Advanced features are often richer than those of a generalist platform. If your needs are highly specific in one area, the specialized tool will likely be superior.
But this approach comes at a cost, and it's not just financial.
The real cost of best-of-breed
The direct financial cost
Take a 10-person agency with a typical best-of-breed stack:
- Project management (Monday Business): 19 euros/user/month = 190 euros
- CRM (Pipedrive Professional): 49 euros/user/month = 490 euros (5 salespeople)
- Time tracking (Toggl Track Business): 13 euros/user/month = 130 euros
- Invoicing (Pennylane): starting at 49 euros/month
- Contracts (DocuSign): 25 euros/user/month = 75 euros (3 users)
- Communication (Slack Pro): 7 euros/user/month = 70 euros
Total: roughly 1,000 euros per month, or 12,000 euros per year. And that doesn't include the Zapier or Make connectors needed to link these tools together (an additional 150 to 300 euros/month).
The hidden cost of integration
The real problem with best-of-breed isn't the unit price of each tool. It's the work required to make them communicate. When a prospect becomes a client in Pipedrive, you need to create a project in Monday, a client in Pennylane, and a folder in Google Drive. Manually, it's a constant source of errors. Through automations (Zapier, Make), it's fragile and expensive to maintain.
And when an automation breaks (a renamed field, a changed API, a plan that no longer includes the integration), the entire chain stops. Time spent debugging zaps is time that produces zero value for your clients.
The cognitive cost
Each tool has its own logic, its own interface, its own shortcuts. Switching between 6 applications in a single day fragments attention. Where's the information about this client? In the CRM? In the project tool? In email? This cognitive cost is invisible but real. It slows everyone down, from juniors to seniors.
The best tool in the world is worthless if it operates in a silo. The value of an information system comes from the connections between its components, not from the individual performance of each one.
The all-in-one approach: the promise of coherence
The alternative is to consolidate as many functions as possible into a single platform. CRM, project management, invoicing, time tracking, contracts, collaboration: one tool, one login, one source of truth.
The benefits are immediate:
- Data continuity: the prospect that becomes a client, then a project, then an invoice, with no data gaps.
- Controlled costs: one subscription instead of six. Often 50 to 70% cheaper than the equivalent best-of-breed stack.
- Simplified onboarding: one tool for the entire team to learn. Training time is cut by a factor of three.
- Zero integration maintenance: no Zapier, no connectors to monitor, no data falling out of sync.
- Global visibility: a single dashboard showing revenue, active projects, hours consumed, and cash flow. Impossible to achieve with separate tools without significant manual consolidation.
Common objections to all-in-one
The most common argument against all-in-one is that each module is less deep than its specialized equivalent. That's sometimes true. An all-in-one CRM probably won't have the predictive scoring of a Salesforce. A built-in invoicing module may not have the bank reconciliation of a dedicated accounting tool.
But the question to ask is: do you actually need those advanced features? An agency of 5 to 50 people needs a clear sales pipeline, well-structured projects, compliant invoices, and reliable time tracking. It doesn't need 200 custom fields in its CRM or a workflow engine with 15 conditions.
The modern all-in-one is no longer the "average at everything" software of the 2010s. Today's platforms offer 90% of the features an agency needs in each area. And the missing 10% is rarely what makes a difference day to day.
How to decide for your agency
Here's a simple decision framework:
- You're an agency with fewer than 50 people: all-in-one is almost always the best choice. The gains in simplicity and cost far outweigh the advanced features you won't use.
- You have a very specific need in one area: for example, if your business model relies on complex recurring billing with tiers, a specialized tool may be justified for that particular module.
- You already have a working stack with stable automations: don't change for the sake of change. But honestly assess how much time you spend maintaining the whole setup.
The market trend is clear. The most efficient agencies are converging toward unified platforms that cover the essentials of their needs. Not because they're lazy, but because they've understood that productivity comes from smooth processes, not from the individual sophistication of each tool. In 2025, the best tool is the one your entire team actually uses, every day, without friction.